From 56d64ebdb762c12f0fc386e014cb3a7904c238a9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=F0=9F=91=A8=F0=9F=8F=BC=E2=80=8D=F0=9F=92=BB=20Romain=20M?=
 =?UTF-8?q?arcadier-Muller?= <rmuller@amazon.com>
Date: Wed, 12 Jun 2019 10:03:57 +0200
Subject: [PATCH 1/5] feat(core): Introduced Duration class

This can be used to model durations in a user-friendly way, while
allowing coercion into the desired/required time unit at the usage site.

There is now a default requirement that properties exposed by the APIs
and that have a duration-like name (ending in `duration`, `period`,
`timeout` or `ttl`) have a type of `@aws-cdk/cdk.Duration` and do not
contain a unit suffix (`Days`, `Millis`, `Seconds`, `Sec`, ...).

BREAKING CHANGE: Properties throughout the AWS Construct Libraries that
                 represent lengths of time have been re-typed to be
                 `@aws-cdk/cdk.Duration` instead of `number`, and were
                 renamed to exclude any unit indication.
---
 .../assets-docker/lib/adopted-repository.ts   |   2 +-
 packages/@aws-cdk/aws-apigateway/lib/stage.ts |  10 +-
 packages/@aws-cdk/aws-apigateway/package.json |   5 +-
 .../lib/step-scaling-action.ts                |   6 +-
 .../lib/step-scaling-policy.ts                |  10 +-
 .../lib/target-tracking-scaling-policy.ts     |  17 +-
 .../aws-autoscaling/lib/auto-scaling-group.ts |  53 +----
 .../aws-autoscaling/lib/lifecycle-hook.ts     |   6 +-
 .../lib/step-scaling-action.ts                |  10 +-
 .../lib/step-scaling-policy.ts                |  12 +-
 .../lib/target-tracking-scaling-policy.ts     |  16 +-
 .../test/test.auto-scaling-group.ts           |   6 +-
 .../lib/dns-validated-certificate.ts          |   2 +-
 .../test/integ.trivial-lambda-resource.ts     |   2 +-
 .../aws-cloudformation/test/test.resource.ts  |   2 +-
 .../aws-cloudfront/lib/web_distribution.ts    |  45 ++--
 packages/@aws-cdk/aws-cloudtrail/package.json |   8 +-
 packages/@aws-cdk/aws-cloudwatch/lib/alarm.ts |   6 +-
 packages/@aws-cdk/aws-cloudwatch/lib/graph.ts |   2 +-
 .../@aws-cdk/aws-cloudwatch/lib/metric.ts     |  33 ++-
 .../aws-cloudwatch/test/test.alarm.ts         |   4 +-
 .../@aws-cdk/aws-codebuild/lib/project.ts     |   8 +-
 packages/@aws-cdk/aws-codebuild/package.json  |   6 +-
 .../aws-codebuild/test/test.codebuild.ts      |   2 +-
 .../@aws-cdk/aws-config/lib/managed-rules.ts  |  12 +-
 .../lib/global-table-coordinator.ts           |   2 +-
 .../lib/scalable-table-attribute.ts           |   4 +-
 packages/@aws-cdk/aws-ec2/test/test.vpn.ts    |   6 +-
 packages/@aws-cdk/aws-ecr/lib/lifecycle.ts    |   8 +-
 packages/@aws-cdk/aws-ecr/lib/repository.ts   |  10 +-
 .../@aws-cdk/aws-ecr/test/test.repository.ts  |   2 +-
 .../@aws-cdk/aws-ecs/lib/base/base-service.ts |  13 +-
 .../aws-ecs/lib/base/scalable-task-count.ts   |  16 +-
 packages/@aws-cdk/aws-ecs/lib/cluster.ts      |  10 +-
 .../aws-ecs/lib/container-definition.ts       |  16 +-
 .../lib/drain-hook/instance-drain-hook.ts     |  16 +-
 .../aws-ecs/lib/log-drivers/aws-log-driver.ts |   6 +-
 .../aws-ecs/test/ec2/test.ec2-service.ts      |   2 +-
 .../test/fargate/test.fargate-service.ts      |   4 +-
 .../aws-ecs/test/test.aws-log-driver.ts       |   4 +-
 .../aws-ecs/test/test.container-definition.ts |  12 +-
 .../lib/load-balancer.ts                      |  14 +-
 .../test/test.loadbalancer.ts                 |   6 +-
 .../lib/alb/application-listener.ts           |  22 +-
 .../lib/alb/application-load-balancer.ts      |   6 +-
 .../lib/alb/application-target-group.ts       |  22 +-
 .../lib/nlb/network-listener.ts               |   8 +-
 .../lib/shared/base-target-group.ts           |  24 +-
 .../test/alb/test.listener.ts                 |   6 +-
 .../test/alb/test.load-balancer.ts            |   2 +-
 .../test/nlb/test.listener.ts                 |   4 +-
 .../test/stepfunctions/statemachine.test.ts   |   2 +-
 packages/@aws-cdk/aws-iam/lib/role.ts         |  16 +-
 packages/@aws-cdk/aws-iam/test/test.role.ts   |  14 +-
 packages/@aws-cdk/aws-lambda/lib/function.ts  |  16 +-
 .../@aws-cdk/aws-lambda/lib/log-retention.ts  |   4 +-
 .../aws-lambda/test/integ.log-retention.ts    |   6 +-
 .../@aws-cdk/aws-lambda/test/test.lambda.ts   |  10 +-
 .../aws-lambda/test/test.log-retention.ts     |   2 +-
 .../aws-lambda/test/test.singleton-lambda.ts  |   2 +-
 packages/@aws-cdk/aws-logs/lib/log-group.ts   |   6 +-
 packages/@aws-cdk/aws-logs/package.json       |   2 +-
 .../aws-logs/test/example.retention.lit.ts    |   4 +-
 .../@aws-cdk/aws-logs/test/test.loggroup.ts   |   6 +-
 packages/@aws-cdk/aws-rds/lib/cluster.ts      |   2 +-
 packages/@aws-cdk/aws-rds/lib/instance.ts     |  18 +-
 packages/@aws-cdk/aws-rds/lib/props.ts        |   4 +-
 .../@aws-cdk/aws-rds/lib/secret-rotation.ts   |   8 +-
 .../aws-rds/test/integ.instance.lit.ts        |   4 +-
 .../@aws-cdk/aws-rds/test/test.instance.ts    | 130 ++++++-----
 .../@aws-cdk/aws-route53/lib/hosted-zone.ts   |   4 +-
 .../@aws-cdk/aws-route53/lib/record-set.ts    |  12 +-
 .../aws-route53/test/integ.route53.ts         |   2 +-
 .../aws-route53/test/test.record-set.ts       |   4 +-
 .../@aws-cdk/aws-route53/test/test.route53.ts |   2 +-
 .../lib/bucket-deployment.ts                  |   2 +-
 packages/@aws-cdk/aws-s3/lib/bucket.ts        |  21 +-
 packages/@aws-cdk/aws-s3/lib/rule.ts          |  12 +-
 packages/@aws-cdk/aws-s3/test/test.rules.ts   |  12 +-
 .../lib/rotation-schedule.ts                  |   8 +-
 .../aws-servicediscovery/lib/service.ts       |  12 +-
 .../integ.service-with-cname-record.lit.ts    |   2 +-
 ....service-with-private-dns-namespace.lit.ts |   2 +-
 ...g.service-with-public-dns-namespace.lit.ts |   2 +-
 packages/@aws-cdk/aws-sns/test/test.sns.ts    |   4 +-
 packages/@aws-cdk/aws-sqs/lib/queue.ts        |  30 +--
 .../@aws-cdk/aws-sqs/lib/validate-props.ts    |   9 +-
 packages/@aws-cdk/aws-sqs/test/test.sqs.ts    |   6 +-
 .../lib/invoke-activity.ts                    |   5 +-
 .../lib/send-to-queue.ts                      |   5 +-
 .../test/integ.job-poller.ts                  |   6 +-
 packages/@aws-cdk/aws-stepfunctions/README.md |   6 +-
 .../aws-stepfunctions/lib/state-graph.ts      |   7 +-
 .../aws-stepfunctions/lib/state-machine.ts    |   6 +-
 .../aws-stepfunctions/lib/states/state.ts     |   4 +-
 .../aws-stepfunctions/lib/states/task.ts      |  10 +-
 .../aws-stepfunctions/lib/states/wait.ts      |  22 +-
 .../lib/step-functions-task.ts                |   3 +-
 .../@aws-cdk/aws-stepfunctions/lib/types.ts   |   7 +-
 .../@aws-cdk/aws-stepfunctions/package.json   |   6 +-
 .../aws-stepfunctions/test/test.activity.ts   |   4 +-
 .../test/test.states-language.ts              |   4 +-
 packages/@aws-cdk/cdk/lib/cfn-resource.ts     |  14 +-
 packages/@aws-cdk/cdk/lib/duration.ts         | 208 ++++++++++++++++++
 packages/@aws-cdk/cdk/lib/index.ts            |   1 +
 packages/@aws-cdk/cdk/lib/resource-policy.ts  |   4 +-
 packages/@aws-cdk/cdk/test/test.duration.ts   |  91 ++++++++
 tools/awslint/bin/awslint.ts                  |   9 +-
 tools/awslint/lib/rules/durations.ts          |  51 +++++
 tools/awslint/lib/rules/index.ts              |  15 +-
 110 files changed, 871 insertions(+), 549 deletions(-)
 create mode 100644 packages/@aws-cdk/cdk/lib/duration.ts
 create mode 100644 packages/@aws-cdk/cdk/test/test.duration.ts
 create mode 100644 tools/awslint/lib/rules/durations.ts

diff --git a/packages/@aws-cdk/assets-docker/lib/adopted-repository.ts b/packages/@aws-cdk/assets-docker/lib/adopted-repository.ts
index 397afb6828b0e..9114c52fc4462 100644
--- a/packages/@aws-cdk/assets-docker/lib/adopted-repository.ts
+++ b/packages/@aws-cdk/assets-docker/lib/adopted-repository.ts
@@ -38,7 +38,7 @@ export class AdoptedRepository extends ecr.RepositoryBase {
       handler: 'handler.handler',
       code: lambda.Code.asset(path.join(__dirname, 'adopt-repository')),
       uuid: 'dbc60def-c595-44bc-aa5c-28c95d68f62c',
-      timeout: 300
+      timeout: cdk.Duration.minutes(5)
     });
 
     fn.addToRolePolicy(new iam.PolicyStatement()
diff --git a/packages/@aws-cdk/aws-apigateway/lib/stage.ts b/packages/@aws-cdk/aws-apigateway/lib/stage.ts
index d89961bbdf2d7..6e4000ca756ba 100644
--- a/packages/@aws-cdk/aws-apigateway/lib/stage.ts
+++ b/packages/@aws-cdk/aws-apigateway/lib/stage.ts
@@ -1,4 +1,4 @@
-import { Construct, Resource, Stack } from '@aws-cdk/cdk';
+import { Construct, Duration, Resource, Stack, toSeconds } from '@aws-cdk/cdk';
 import { CfnStage } from './apigateway.generated';
 import { Deployment } from './deployment';
 import { IRestApi } from './restapi';
@@ -145,9 +145,9 @@ export interface MethodDeploymentOptions {
    * higher the TTL, the longer the response will be cached.
    * @see https://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-caching.html
    *
-   * @default 300
+   * @default Duration.minutes(5)
    */
-  readonly cacheTtlSeconds?: number;
+  readonly cacheTtl?: Duration;
 
   /**
    * Indicates whether the cached responses are encrypted.
@@ -224,7 +224,7 @@ export class Stage extends Resource {
       throttlingBurstLimit: props.throttlingBurstLimit,
       throttlingRateLimit: props.throttlingRateLimit,
       cachingEnabled: props.cachingEnabled,
-      cacheTtlSeconds: props.cacheTtlSeconds,
+      cacheTtl: props.cacheTtl,
       cacheDataEncrypted: props.cacheDataEncrypted
     };
 
@@ -256,7 +256,7 @@ export class Stage extends Resource {
       return {
         httpMethod, resourcePath,
         cacheDataEncrypted: options.cacheDataEncrypted,
-        cacheTtlInSeconds: options.cacheTtlSeconds,
+        cacheTtlInSeconds: toSeconds(options.cacheTtl),
         cachingEnabled: options.cachingEnabled,
         dataTraceEnabled: options.dataTraceEnabled,
         loggingLevel: options.loggingLevel,
diff --git a/packages/@aws-cdk/aws-apigateway/package.json b/packages/@aws-cdk/aws-apigateway/package.json
index 48eac7de08339..e13c17c2974fd 100644
--- a/packages/@aws-cdk/aws-apigateway/package.json
+++ b/packages/@aws-cdk/aws-apigateway/package.json
@@ -91,8 +91,9 @@
   },
   "awslint": {
     "exclude": [
-      "from-method:@aws-cdk/aws-apigateway.Resource"
+      "from-method:@aws-cdk/aws-apigateway.Resource",
+      "duration-prop-type:@aws-cdk/aws-apigateway.QuotaSettings.period"
     ]
   },
   "stability": "experimental"
-}
\ No newline at end of file
+}
diff --git a/packages/@aws-cdk/aws-applicationautoscaling/lib/step-scaling-action.ts b/packages/@aws-cdk/aws-applicationautoscaling/lib/step-scaling-action.ts
index b9c042022c9be..bb9fe106377c8 100644
--- a/packages/@aws-cdk/aws-applicationautoscaling/lib/step-scaling-action.ts
+++ b/packages/@aws-cdk/aws-applicationautoscaling/lib/step-scaling-action.ts
@@ -37,7 +37,7 @@ export interface StepScalingActionProps {
    * @see https://docs.aws.amazon.com/autoscaling/application/APIReference/API_StepScalingPolicyConfiguration.html
    * @default No cooldown period
    */
-  readonly cooldownSec?: number;
+  readonly cooldown?: cdk.Duration;
 
   /**
    * Minimum absolute number to adjust capacity with as result of percentage scaling.
@@ -86,7 +86,7 @@ export class StepScalingAction extends cdk.Construct {
       scalingTargetId: props.scalingTarget.scalableTargetId,
       stepScalingPolicyConfiguration: {
         adjustmentType: props.adjustmentType,
-        cooldown: props.cooldownSec,
+        cooldown: cdk.toSeconds(props.cooldown),
         minAdjustmentMagnitude: props.minAdjustmentMagnitude,
         metricAggregationType: props.metricAggregationType,
         stepAdjustments: cdk.Lazy.anyValue({ produce: () => this.adjustments }),
@@ -190,4 +190,4 @@ export interface AdjustmentTier {
    * @default +Infinity
    */
   readonly upperBound?: number;
-}
\ No newline at end of file
+}
diff --git a/packages/@aws-cdk/aws-applicationautoscaling/lib/step-scaling-policy.ts b/packages/@aws-cdk/aws-applicationautoscaling/lib/step-scaling-policy.ts
index 3b178dca42bab..7b91b513b7eff 100644
--- a/packages/@aws-cdk/aws-applicationautoscaling/lib/step-scaling-policy.ts
+++ b/packages/@aws-cdk/aws-applicationautoscaling/lib/step-scaling-policy.ts
@@ -35,7 +35,7 @@ export interface BasicStepScalingPolicyProps {
    * @see https://docs.aws.amazon.com/autoscaling/application/APIReference/API_StepScalingPolicyConfiguration.html
    * @default No cooldown period
    */
-  readonly cooldownSec?: number;
+  readonly cooldown?: cdk.Duration;
 
   /**
    * Minimum absolute number to adjust capacity with as result of percentage scaling.
@@ -86,7 +86,7 @@ export class StepScalingPolicy extends cdk.Construct {
 
       this.lowerAction = new StepScalingAction(this, 'LowerPolicy', {
         adjustmentType,
-        cooldownSec: props.cooldownSec,
+        cooldown: props.cooldown,
         metricAggregationType: aggregationTypeFromMetric(props.metric),
         minAdjustmentMagnitude: props.minAdjustmentMagnitude,
         scalingTarget: props.scalingTarget,
@@ -102,7 +102,7 @@ export class StepScalingPolicy extends cdk.Construct {
 
       this.lowerAlarm = new cloudwatch.Alarm(this, 'LowerAlarm', {
         // Recommended by AutoScaling
-        metric: props.metric.with({ periodSec: 60 }),
+        metric: props.metric.with({ period: cdk.Duration.minutes(1) }),
         alarmDescription: 'Lower threshold scaling alarm',
         comparisonOperator: cloudwatch.ComparisonOperator.LessThanOrEqualToThreshold,
         evaluationPeriods: 1,
@@ -116,7 +116,7 @@ export class StepScalingPolicy extends cdk.Construct {
 
       this.upperAction = new StepScalingAction(this, 'UpperPolicy', {
         adjustmentType,
-        cooldownSec: props.cooldownSec,
+        cooldown: props.cooldown,
         metricAggregationType: aggregationTypeFromMetric(props.metric),
         minAdjustmentMagnitude: props.minAdjustmentMagnitude,
         scalingTarget: props.scalingTarget,
@@ -132,7 +132,7 @@ export class StepScalingPolicy extends cdk.Construct {
 
       this.upperAlarm = new cloudwatch.Alarm(this, 'UpperAlarm', {
         // Recommended by AutoScaling
-        metric: props.metric.with({ periodSec: 60 }),
+        metric: props.metric.with({ period: cdk.Duration.minutes(1) }),
         alarmDescription: 'Upper threshold scaling alarm',
         comparisonOperator: cloudwatch.ComparisonOperator.GreaterThanOrEqualToThreshold,
         evaluationPeriods: 1,
diff --git a/packages/@aws-cdk/aws-applicationautoscaling/lib/target-tracking-scaling-policy.ts b/packages/@aws-cdk/aws-applicationautoscaling/lib/target-tracking-scaling-policy.ts
index 3e5a6733aeef4..4c653c5a721e8 100644
--- a/packages/@aws-cdk/aws-applicationautoscaling/lib/target-tracking-scaling-policy.ts
+++ b/packages/@aws-cdk/aws-applicationautoscaling/lib/target-tracking-scaling-policy.ts
@@ -37,14 +37,14 @@ export interface BaseTargetTrackingProps {
    *
    * @default - No scale in cooldown.
    */
-  readonly scaleInCooldownSec?: number;
+  readonly scaleInCooldown?: cdk.Duration;
 
   /**
    * Period after a scale out activity completes before another scale out activity can start.
    *
    * @default - No scale out cooldown.
    */
-  readonly scaleOutCooldownSec?: number;
+  readonly scaleOutCooldown?: cdk.Duration;
 }
 
 /**
@@ -115,13 +115,6 @@ export class TargetTrackingScalingPolicy extends cdk.Construct {
       throw new Error(`Exactly one of 'customMetric' or 'predefinedMetric' must be specified.`);
     }
 
-    if (props.scaleInCooldownSec !== undefined && props.scaleInCooldownSec < 0) {
-      throw new RangeError(`scaleInCooldown cannot be negative, got: ${props.scaleInCooldownSec}`);
-    }
-    if (props.scaleOutCooldownSec !== undefined && props.scaleOutCooldownSec < 0) {
-      throw new RangeError(`scaleOutCooldown cannot be negative, got: ${props.scaleOutCooldownSec}`);
-    }
-
     super(scope, id);
 
     const resource = new CfnScalingPolicy(this, 'Resource', {
@@ -135,8 +128,8 @@ export class TargetTrackingScalingPolicy extends cdk.Construct {
           predefinedMetricType: props.predefinedMetric,
           resourceLabel: props.resourceLabel,
         } : undefined,
-        scaleInCooldown: props.scaleInCooldownSec,
-        scaleOutCooldown: props.scaleOutCooldownSec,
+        scaleInCooldown: cdk.toSeconds(props.scaleInCooldown),
+        scaleOutCooldown: cdk.toSeconds(props.scaleOutCooldown),
         targetValue: props.targetValue
       }
     });
@@ -171,4 +164,4 @@ export enum PredefinedMetric {
   SageMakerVariantInvocationsPerInstance = 'SageMakerVariantInvocationsPerInstance',
   ECSServiceAverageCPUUtilization = 'ECSServiceAverageCPUUtilization',
   ECSServiceAverageMemoryUtilization = 'ECSServiceAverageMemoryUtilization',
-}
\ No newline at end of file
+}
diff --git a/packages/@aws-cdk/aws-autoscaling/lib/auto-scaling-group.ts b/packages/@aws-cdk/aws-autoscaling/lib/auto-scaling-group.ts
index ba8f4363fb12a..88936e254aff9 100644
--- a/packages/@aws-cdk/aws-autoscaling/lib/auto-scaling-group.ts
+++ b/packages/@aws-cdk/aws-autoscaling/lib/auto-scaling-group.ts
@@ -5,7 +5,7 @@ import elbv2 = require('@aws-cdk/aws-elasticloadbalancingv2');
 import iam = require('@aws-cdk/aws-iam');
 import sns = require('@aws-cdk/aws-sns');
 
-import { AutoScalingRollingUpdate, Construct, Fn, IResource, Lazy, Resource, Tag } from '@aws-cdk/cdk';
+import { AutoScalingRollingUpdate, Construct, Duration, Fn, IResource, Lazy, Resource, Tag } from '@aws-cdk/cdk';
 import { CfnAutoScalingGroup, CfnAutoScalingGroupProps, CfnLaunchConfiguration } from './autoscaling.generated';
 import { BasicLifecycleHookProps, LifecycleHook } from './lifecycle-hook';
 import { BasicScheduledActionProps, ScheduledAction } from './scheduled-action';
@@ -130,16 +130,16 @@ export interface CommonAutoScalingGroupProps {
    *
    * The maximum value is 43200 (12 hours).
    *
-   * @default 300 (5 minutes)
+   * @default Duration.minutes(5)
    */
-  readonly resourceSignalTimeoutSec?: number;
+  readonly resourceSignalTimeout?: Duration;
 
   /**
    * Default scaling cooldown for this AutoScalingGroup
    *
-   * @default 300 (5 minutes)
+   * @default Duration.minutes(5)
    */
-  readonly cooldownSeconds?: number;
+  readonly cooldown?: Duration;
 
   /**
    * Whether instances in the Auto Scaling Group should have public
@@ -353,10 +353,6 @@ export class AutoScalingGroup extends AutoScalingGroupBase implements
   constructor(scope: Construct, id: string, props: AutoScalingGroupProps) {
     super(scope, id);
 
-    if (props.cooldownSeconds !== undefined && props.cooldownSeconds < 0) {
-      throw new RangeError(`cooldownSeconds cannot be negative, got: ${props.cooldownSeconds}`);
-    }
-
     this.securityGroup = new ec2.SecurityGroup(this, 'InstanceSecurityGroup', {
       vpc: props.vpc,
       allowAllOutbound: props.allowAllOutbound !== false
@@ -404,7 +400,7 @@ export class AutoScalingGroup extends AutoScalingGroupBase implements
 
     const { subnetIds } = props.vpc.selectSubnets(props.vpcSubnets);
     const asgProps: CfnAutoScalingGroupProps = {
-      cooldown: props.cooldownSeconds !== undefined ? `${props.cooldownSeconds}` : undefined,
+      cooldown: props.cooldown !== undefined ? `${props.cooldown}` : undefined,
       minSize: minCapacity.toString(),
       maxSize: maxCapacity.toString(),
       desiredCapacity: desiredCapacity.toString(),
@@ -526,12 +522,12 @@ export class AutoScalingGroup extends AutoScalingGroupBase implements
       };
     }
 
-    if (props.resourceSignalCount !== undefined || props.resourceSignalTimeoutSec !== undefined) {
+    if (props.resourceSignalCount !== undefined || props.resourceSignalTimeout !== undefined) {
       this.autoScalingGroup.options.creationPolicy = {
         ...this.autoScalingGroup.options.creationPolicy,
         resourceSignal: {
           count: props.resourceSignalCount,
-          timeout: props.resourceSignalTimeoutSec !== undefined ? renderIsoDuration(props.resourceSignalTimeoutSec) : undefined,
+          timeout: props.resourceSignalTimeout,
         }
       };
     }
@@ -605,9 +601,9 @@ export interface RollingUpdateConfiguration {
    * PT#H#M#S, where each # is the number of hours, minutes, and seconds,
    * respectively). The maximum PauseTime is one hour (PT1H).
    *
-   * @default 300 if the waitOnResourceSignals property is true, otherwise 0
+   * @default Duration.minutes(5) if the waitOnResourceSignals property is true, otherwise 0
    */
-  readonly pauseTimeSec?: number;
+  readonly pauseTime?: Duration;
 
   /**
    * Specifies whether the Auto Scaling group waits on signals from new instances during an update.
@@ -651,14 +647,14 @@ export enum ScalingProcess {
  */
 function renderRollingUpdateConfig(config: RollingUpdateConfiguration = {}): AutoScalingRollingUpdate {
   const waitOnResourceSignals = config.minSuccessfulInstancesPercent !== undefined ? true : false;
-  const pauseTimeSec = config.pauseTimeSec !== undefined ? config.pauseTimeSec : (waitOnResourceSignals ? 300 : 0);
+  const pauseTime = config.pauseTime || (waitOnResourceSignals ? Duration.minutes(5) : Duration.seconds(0));
 
   return {
     maxBatchSize: config.maxBatchSize,
     minInstancesInService: config.minInstancesInService,
     minSuccessfulInstancesPercent: validatePercentage(config.minSuccessfulInstancesPercent),
     waitOnResourceSignals,
-    pauseTime: renderIsoDuration(pauseTimeSec),
+    pauseTime: pauseTime && pauseTime.toISOString(),
     suspendProcesses: config.suspendProcesses !== undefined ? config.suspendProcesses :
       // Recommended list of processes to suspend from here:
       // https://aws.amazon.com/premiumsupport/knowledge-center/auto-scaling-group-rolling-updates/
@@ -667,31 +663,6 @@ function renderRollingUpdateConfig(config: RollingUpdateConfiguration = {}): Aut
   };
 }
 
-/**
- * Render a number of seconds to a PTnX string.
- */
-function renderIsoDuration(seconds: number): string {
-  const ret: string[] = [];
-
-  if (seconds === 0) {
-    return 'PT0S';
-  }
-
-  if (seconds >= 3600) {
-    ret.push(`${Math.floor(seconds / 3600)}H`);
-    seconds %= 3600;
-  }
-  if (seconds >= 60) {
-    ret.push(`${Math.floor(seconds / 60)}M`);
-    seconds %= 60;
-  }
-  if (seconds > 0) {
-    ret.push(`${seconds}S`);
-  }
-
-  return 'PT' + ret.join('');
-}
-
 function validatePercentage(x?: number): number | undefined {
   if (x === undefined || (0 <= x && x <= 100)) { return x; }
   throw new Error(`Expected: a percentage 0..100, got: ${x}`);
diff --git a/packages/@aws-cdk/aws-autoscaling/lib/lifecycle-hook.ts b/packages/@aws-cdk/aws-autoscaling/lib/lifecycle-hook.ts
index 5859f2b969584..4292008bc49c0 100644
--- a/packages/@aws-cdk/aws-autoscaling/lib/lifecycle-hook.ts
+++ b/packages/@aws-cdk/aws-autoscaling/lib/lifecycle-hook.ts
@@ -1,5 +1,5 @@
 import iam = require('@aws-cdk/aws-iam');
-import { Construct, IResource, Resource } from '@aws-cdk/cdk';
+import { Construct, Duration, IResource, Resource, toSeconds } from '@aws-cdk/cdk';
 import { IAutoScalingGroup } from './auto-scaling-group';
 import { CfnLifecycleHook } from './autoscaling.generated';
 import { ILifecycleHookTarget } from './lifecycle-hook-target';
@@ -29,7 +29,7 @@ export interface BasicLifecycleHookProps {
    *
    * @default - No heartbeat timeout.
    */
-  readonly heartbeatTimeoutSec?: number;
+  readonly heartbeatTimeout?: Duration;
 
   /**
    * The state of the Amazon EC2 instance to which you want to attach the lifecycle hook.
@@ -103,7 +103,7 @@ export class LifecycleHook extends Resource implements ILifecycleHook {
     const resource = new CfnLifecycleHook(this, 'Resource', {
       autoScalingGroupName: props.autoScalingGroup.autoScalingGroupName,
       defaultResult: props.defaultResult,
-      heartbeatTimeout: props.heartbeatTimeoutSec,
+      heartbeatTimeout: toSeconds(props.heartbeatTimeout),
       lifecycleHookName: props.lifecycleHookName,
       lifecycleTransition: props.lifecycleTransition,
       notificationMetadata: props.notificationMetadata,
diff --git a/packages/@aws-cdk/aws-autoscaling/lib/step-scaling-action.ts b/packages/@aws-cdk/aws-autoscaling/lib/step-scaling-action.ts
index a0eeed3f0fca4..892010ec9d247 100644
--- a/packages/@aws-cdk/aws-autoscaling/lib/step-scaling-action.ts
+++ b/packages/@aws-cdk/aws-autoscaling/lib/step-scaling-action.ts
@@ -16,14 +16,14 @@ export interface StepScalingActionProps {
    *
    * @default The default cooldown configured on the AutoScalingGroup
    */
-  readonly cooldownSeconds?: number;
+  readonly cooldown?: cdk.Duration;
 
   /**
    * Estimated time until a newly launched instance can send metrics to CloudWatch.
    *
    * @default Same as the cooldown
    */
-  readonly estimatedInstanceWarmupSeconds?: number;
+  readonly estimatedInstanceWarmup?: cdk.Duration;
 
   /**
    * How the adjustment numbers are interpreted
@@ -73,8 +73,8 @@ export class StepScalingAction extends cdk.Construct {
     const resource = new CfnScalingPolicy(this, 'Resource', {
       policyType: 'StepScaling',
       autoScalingGroupName: props.autoScalingGroup.autoScalingGroupName,
-      cooldown: props.cooldownSeconds !== undefined ? `${props.cooldownSeconds}` : undefined,
-      estimatedInstanceWarmup: props.estimatedInstanceWarmupSeconds,
+      cooldown: props.cooldown && props.cooldown.toSeconds().toString(),
+      estimatedInstanceWarmup: cdk.toSeconds(props.estimatedInstanceWarmup),
       adjustmentType: props.adjustmentType,
       minAdjustmentMagnitude: props.minAdjustmentMagnitude,
       metricAggregationType: props.metricAggregationType,
@@ -178,4 +178,4 @@ export interface AdjustmentTier {
    * @default +Infinity
    */
   readonly upperBound?: number;
-}
\ No newline at end of file
+}
diff --git a/packages/@aws-cdk/aws-autoscaling/lib/step-scaling-policy.ts b/packages/@aws-cdk/aws-autoscaling/lib/step-scaling-policy.ts
index 3e3a126a4391d..df0abdb09cf56 100644
--- a/packages/@aws-cdk/aws-autoscaling/lib/step-scaling-policy.ts
+++ b/packages/@aws-cdk/aws-autoscaling/lib/step-scaling-policy.ts
@@ -29,14 +29,14 @@ export interface BasicStepScalingPolicyProps {
    *
    * @default Default cooldown period on your AutoScalingGroup
    */
-  readonly cooldownSeconds?: number;
+  readonly cooldown?: cdk.Duration;
 
   /**
    * Estimated time until a newly launched instance can send metrics to CloudWatch.
    *
    * @default Same as the cooldown
    */
-  readonly estimatedInstanceWarmupSeconds?: number;
+  readonly estimatedInstanceWarmup?: cdk.Duration;
 
   /**
    * Minimum absolute number to adjust capacity with as result of percentage scaling.
@@ -87,7 +87,7 @@ export class StepScalingPolicy extends cdk.Construct {
 
       this.lowerAction = new StepScalingAction(this, 'LowerPolicy', {
         adjustmentType: props.adjustmentType,
-        cooldownSeconds: props.cooldownSeconds,
+        cooldown: props.cooldown,
         metricAggregationType: aggregationTypeFromMetric(props.metric),
         minAdjustmentMagnitude: props.minAdjustmentMagnitude,
         autoScalingGroup: props.autoScalingGroup,
@@ -103,7 +103,7 @@ export class StepScalingPolicy extends cdk.Construct {
 
       this.lowerAlarm = new cloudwatch.Alarm(this, 'LowerAlarm', {
         // Recommended by AutoScaling
-        metric: props.metric.with({ periodSec: 60 }),
+        metric: props.metric.with({ period: cdk.Duration.minutes(1) }),
         alarmDescription: 'Lower threshold scaling alarm',
         comparisonOperator: cloudwatch.ComparisonOperator.LessThanOrEqualToThreshold,
         evaluationPeriods: 1,
@@ -117,7 +117,7 @@ export class StepScalingPolicy extends cdk.Construct {
 
       this.upperAction = new StepScalingAction(this, 'UpperPolicy', {
         adjustmentType: props.adjustmentType,
-        cooldownSeconds: props.cooldownSeconds,
+        cooldown: props.cooldown,
         metricAggregationType: aggregationTypeFromMetric(props.metric),
         minAdjustmentMagnitude: props.minAdjustmentMagnitude,
         autoScalingGroup: props.autoScalingGroup,
@@ -133,7 +133,7 @@ export class StepScalingPolicy extends cdk.Construct {
 
       this.upperAlarm = new cloudwatch.Alarm(this, 'UpperAlarm', {
         // Recommended by AutoScaling
-        metric: props.metric.with({ periodSec: 60 }),
+        metric: props.metric.with({ period: cdk.Duration.minutes(1) }),
         alarmDescription: 'Upper threshold scaling alarm',
         comparisonOperator: cloudwatch.ComparisonOperator.GreaterThanOrEqualToThreshold,
         evaluationPeriods: 1,
diff --git a/packages/@aws-cdk/aws-autoscaling/lib/target-tracking-scaling-policy.ts b/packages/@aws-cdk/aws-autoscaling/lib/target-tracking-scaling-policy.ts
index 7074f87d12882..29c65923dace5 100644
--- a/packages/@aws-cdk/aws-autoscaling/lib/target-tracking-scaling-policy.ts
+++ b/packages/@aws-cdk/aws-autoscaling/lib/target-tracking-scaling-policy.ts
@@ -29,14 +29,14 @@ export interface BaseTargetTrackingProps {
    *
    * @default - The default cooldown configured on the AutoScalingGroup.
    */
-  readonly cooldownSeconds?: number;
+  readonly cooldown?: cdk.Duration;
 
   /**
    * Estimated time until a newly launched instance can send metrics to CloudWatch.
    *
    * @default - Same as the cooldown.
    */
-  readonly estimatedInstanceWarmupSeconds?: number;
+  readonly estimatedInstanceWarmup?: cdk.Duration;
 }
 
 /**
@@ -113,14 +113,6 @@ export class TargetTrackingScalingPolicy extends cdk.Construct {
       throw new Error(`Exactly one of 'customMetric' or 'predefinedMetric' must be specified.`);
     }
 
-    if (props.cooldownSeconds !== undefined && props.cooldownSeconds < 0) {
-      throw new RangeError(`cooldownSeconds cannot be negative, got: ${props.cooldownSeconds}`);
-    }
-
-    if (props.estimatedInstanceWarmupSeconds !== undefined && props.estimatedInstanceWarmupSeconds < 0) {
-      throw new RangeError(`estimatedInstanceWarmupSeconds cannot be negative, got: ${props.estimatedInstanceWarmupSeconds}`);
-    }
-
     if (props.predefinedMetric === PredefinedMetric.ALBRequestCountPerTarget && !props.resourceLabel) {
       throw new Error('When tracking the ALBRequestCountPerTarget metric, the ALB identifier must be supplied in resourceLabel');
     }
@@ -130,8 +122,8 @@ export class TargetTrackingScalingPolicy extends cdk.Construct {
     this.resource = new CfnScalingPolicy(this, 'Resource', {
       policyType: 'TargetTrackingScaling',
       autoScalingGroupName: props.autoScalingGroup.autoScalingGroupName,
-      cooldown: props.cooldownSeconds !== undefined ? `${props.cooldownSeconds}` : undefined,
-      estimatedInstanceWarmup: props.estimatedInstanceWarmupSeconds,
+      cooldown: props.cooldown && props.cooldown.toSeconds().toString(),
+      estimatedInstanceWarmup: cdk.toSeconds(props.estimatedInstanceWarmup),
       targetTrackingConfiguration: {
         customizedMetricSpecification: renderCustomMetric(props.customMetric),
         disableScaleIn: props.disableScaleIn,
diff --git a/packages/@aws-cdk/aws-autoscaling/test/test.auto-scaling-group.ts b/packages/@aws-cdk/aws-autoscaling/test/test.auto-scaling-group.ts
index 72fe66b8dc838..2c5237862f27d 100644
--- a/packages/@aws-cdk/aws-autoscaling/test/test.auto-scaling-group.ts
+++ b/packages/@aws-cdk/aws-autoscaling/test/test.auto-scaling-group.ts
@@ -294,7 +294,7 @@ export = {
       updateType: autoscaling.UpdateType.RollingUpdate,
       rollingUpdateConfiguration: {
         minSuccessfulInstancesPercent: 50,
-        pauseTimeSec: 345
+        pauseTime: cdk.Duration.seconds(345)
       }
     });
 
@@ -324,7 +324,7 @@ export = {
       machineImage: new ec2.AmazonLinuxImage(),
       vpc,
       resourceSignalCount: 5,
-      resourceSignalTimeoutSec: 666
+      resourceSignalTimeout: cdk.Duration.seconds(666)
     });
 
     // THEN
@@ -379,7 +379,7 @@ export = {
       updateType: autoscaling.UpdateType.RollingUpdate,
       rollingUpdateConfiguration: {
         minSuccessfulInstancesPercent: 50,
-        pauseTimeSec: 345
+        pauseTime: cdk.Duration.seconds(345)
       },
     });
     asg.node.applyAspect(new cdk.Tag('superfood', 'acai'));
diff --git a/packages/@aws-cdk/aws-certificatemanager/lib/dns-validated-certificate.ts b/packages/@aws-cdk/aws-certificatemanager/lib/dns-validated-certificate.ts
index e329df9ec4263..cfca14a248a9b 100644
--- a/packages/@aws-cdk/aws-certificatemanager/lib/dns-validated-certificate.ts
+++ b/packages/@aws-cdk/aws-certificatemanager/lib/dns-validated-certificate.ts
@@ -51,7 +51,7 @@ export class DnsValidatedCertificate extends cdk.Resource implements ICertificat
             code: lambda.Code.asset(path.resolve(__dirname, '..', 'lambda-packages', 'dns_validated_certificate_handler', 'lib')),
             handler: 'index.certificateRequestHandler',
             runtime: lambda.Runtime.NodeJS810,
-            timeout: 15 * 60 // 15 minutes
+            timeout: cdk.Duration.minutes(15)
         });
         requestorFunction.addToRolePolicy(
             new iam.PolicyStatement()
diff --git a/packages/@aws-cdk/aws-cloudformation/test/integ.trivial-lambda-resource.ts b/packages/@aws-cdk/aws-cloudformation/test/integ.trivial-lambda-resource.ts
index acc41d471a5b7..f085f70568acf 100644
--- a/packages/@aws-cdk/aws-cloudformation/test/integ.trivial-lambda-resource.ts
+++ b/packages/@aws-cdk/aws-cloudformation/test/integ.trivial-lambda-resource.ts
@@ -27,7 +27,7 @@ class DemoResource extends cdk.Construct {
         // This makes the demo only work as top-level TypeScript program, but that's fine for now
         code: new lambda.InlineCode(fs.readFileSync('integ.trivial-lambda-provider.py', { encoding: 'utf-8' })),
         handler: 'index.main',
-        timeout: 300,
+        timeout: cdk.Duration.minutes(5),
         runtime: lambda.Runtime.Python27,
       })),
       properties: props
diff --git a/packages/@aws-cdk/aws-cloudformation/test/test.resource.ts b/packages/@aws-cdk/aws-cloudformation/test/test.resource.ts
index 29cdb2ff2d22d..3623c0335916c 100644
--- a/packages/@aws-cdk/aws-cloudformation/test/test.resource.ts
+++ b/packages/@aws-cdk/aws-cloudformation/test/test.resource.ts
@@ -149,7 +149,7 @@ class TestCustomResource extends cdk.Construct {
       code: new lambda.InlineCode('def hello(): pass'),
       runtime: lambda.Runtime.Python27,
       handler: 'index.hello',
-      timeout: 300,
+      timeout: cdk.Duration.minutes(5),
     });
 
     new CustomResource(this, 'Resource', {
diff --git a/packages/@aws-cdk/aws-cloudfront/lib/web_distribution.ts b/packages/@aws-cdk/aws-cloudfront/lib/web_distribution.ts
index 6fa422aee3775..b8fa20585dd9f 100644
--- a/packages/@aws-cdk/aws-cloudfront/lib/web_distribution.ts
+++ b/packages/@aws-cdk/aws-cloudfront/lib/web_distribution.ts
@@ -193,9 +193,9 @@ export interface CustomOriginConfig {
   /**
    * The keep alive timeout when making calls in seconds.
    *
-   * @default 5
+   * @default Duration.seconds(5)
    */
-  readonly originKeepaliveTimeoutSeconds?: number,
+  readonly originKeepaliveTimeout?: cdk.Duration,
 
   /**
    * The protocol (http or https) policy to use when interacting with the origin.
@@ -207,9 +207,9 @@ export interface CustomOriginConfig {
   /**
    * The read timeout when calling the origin in seconds
    *
-   * @default 30
+   * @default Duration.seconds(30)
    */
-  readonly originReadTimeoutSeconds?: number
+  readonly originReadTimeout?: cdk.Duration
 
   /**
    * The SSL versions to use when interacting with the origin.
@@ -299,7 +299,7 @@ export interface Behavior {
    * @default 86400 (1 day)
    *
    */
-  readonly defaultTtlSeconds?: number;
+  readonly defaultTtl?: cdk.Duration;
 
   /**
    * The method this CloudFront distribution responds do.
@@ -334,37 +334,18 @@ export interface Behavior {
    * The minimum amount of time that you want objects to stay in the cache
    * before CloudFront queries your origin.
    */
-  readonly minTtlSeconds?: number;
+  readonly minTtl?: cdk.Duration;
 
   /**
    * The max amount of time you want objects to stay in the cache
    * before CloudFront queries your origin.
    *
-   * @default 31536000 (one year)
+   * @default Duration.seconds(31536000) (one year)
    */
-  readonly maxTtlSeconds?: number;
+  readonly maxTtl?: cdk.Duration;
 
 }
 
-export interface ErrorConfiguration {
-  /**
-   * The error code matched from the origin
-   */
-  readonly originErrorCode: number;
-  /**
-   * The error code that is sent to the caller.
-   */
-  readonly respondWithErrorCode: number;
-  /**
-   * The path to service instead
-   */
-  readonly respondWithPage: string;
-  /**
-   * How long before this error is retried.
-   */
-  readonly cacheTtl?: number;
-}
-
 export interface CloudFrontWebDistributionProps {
 
   /**
@@ -582,8 +563,8 @@ export class CloudFrontWebDistribution extends cdk.Construct implements IDistrib
           ? {
             httpPort: originConfig.customOriginSource.httpPort || 80,
             httpsPort: originConfig.customOriginSource.httpsPort || 443,
-            originKeepaliveTimeout: originConfig.customOriginSource.originKeepaliveTimeoutSeconds || 5,
-            originReadTimeout: originConfig.customOriginSource.originReadTimeoutSeconds || 30,
+            originKeepaliveTimeout: cdk.toSeconds(originConfig.customOriginSource.originKeepaliveTimeout) || 5,
+            originReadTimeout: cdk.toSeconds(originConfig.customOriginSource.originReadTimeout) || 30,
             originProtocolPolicy: originConfig.customOriginSource.originProtocolPolicy || OriginProtocolPolicy.HttpsOnly,
             originSslProtocols: originConfig.customOriginSource.allowedOriginSSLVersions || [OriginSslPolicy.TLSv1_2]
           }
@@ -680,10 +661,10 @@ export class CloudFrontWebDistribution extends cdk.Construct implements IDistrib
       allowedMethods: this.METHOD_LOOKUP_MAP[input.allowedMethods || CloudFrontAllowedMethods.GET_HEAD],
       cachedMethods: this.METHOD_LOOKUP_MAP[input.cachedMethods || CloudFrontAllowedCachedMethods.GET_HEAD],
       compress: input.compress,
-      defaultTtl: input.defaultTtlSeconds,
+      defaultTtl: cdk.toSeconds(input.defaultTtl),
       forwardedValues: input.forwardedValues || { queryString: false, cookies: { forward: "none" } },
-      maxTtl: input.maxTtlSeconds,
-      minTtl: input.minTtlSeconds,
+      maxTtl: cdk.toSeconds(input.maxTtl),
+      minTtl: cdk.toSeconds(input.minTtl),
       trustedSigners: input.trustedSigners,
       targetOriginId: input.targetOriginId,
       viewerProtocolPolicy: protoPolicy || ViewerProtocolPolicy.RedirectToHTTPS,
diff --git a/packages/@aws-cdk/aws-cloudtrail/package.json b/packages/@aws-cdk/aws-cloudtrail/package.json
index 039d6e2009b20..5b64f9eb0a2a0 100644
--- a/packages/@aws-cdk/aws-cloudtrail/package.json
+++ b/packages/@aws-cdk/aws-cloudtrail/package.json
@@ -88,8 +88,14 @@
     "@aws-cdk/aws-s3": "^0.34.0",
     "@aws-cdk/cdk": "^0.34.0"
   },
+  "awslint": {
+    "exclude": [
+      "duration-prop-type:@aws-cdk/aws-cloudtrail.TrailProps.cloudWatchLogsRetentionTimeDays",
+      "duration-prop-name:@aws-cdk/aws-cloudtrail.TrailProps.cloudWatchLogsRetentionTimeDays"
+    ]
+  },
   "engines": {
     "node": ">= 8.10.0"
   },
   "stability": "experimental"
-}
\ No newline at end of file
+}
diff --git a/packages/@aws-cdk/aws-cloudwatch/lib/alarm.ts b/packages/@aws-cdk/aws-cloudwatch/lib/alarm.ts
index 52097fc45b6e6..f56abaef6a39f 100644
--- a/packages/@aws-cdk/aws-cloudwatch/lib/alarm.ts
+++ b/packages/@aws-cdk/aws-cloudwatch/lib/alarm.ts
@@ -146,7 +146,7 @@ export class Alarm extends Resource implements IAlarm {
     this.metric = props.metric;
     this.annotation = {
       // tslint:disable-next-line:max-line-length
-      label: `${this.metric.label || this.metric.metricName} ${OPERATOR_SYMBOLS[comparisonOperator]} ${props.threshold} for ${props.evaluationPeriods} datapoints within ${describePeriod(props.evaluationPeriods * props.metric.periodSec)}`,
+      label: `${this.metric.label || this.metric.metricName} ${OPERATOR_SYMBOLS[comparisonOperator]} ${props.threshold} for ${props.evaluationPeriods} datapoints within ${describePeriod(props.evaluationPeriods * props.metric.period.toSeconds())}`,
       value: props.threshold,
     };
   }
@@ -235,7 +235,7 @@ function metricJson(metric: Metric): AlarmMetricJson {
     dimensions: dims.length > 0 ? dims : undefined,
     namespace: metric.namespace,
     metricName: metric.metricName,
-    period: metric.periodSec,
+    period: metric.period.toSeconds(),
     statistic: stat.type === 'simple' ? stat.statistic : undefined,
     extendedStatistic: stat.type === 'percentile' ? 'p' + stat.percentile : undefined,
     unit: metric.unit
@@ -245,7 +245,7 @@ function metricJson(metric: Metric): AlarmMetricJson {
 /**
  * Properties used to construct the Metric identifying part of an Alarm
  */
-export interface AlarmMetricJson {
+interface AlarmMetricJson {
   /**
    * The dimensions to apply to the alarm
    */
diff --git a/packages/@aws-cdk/aws-cloudwatch/lib/graph.ts b/packages/@aws-cdk/aws-cloudwatch/lib/graph.ts
index 249d0c0a739ed..de27848880fc0 100644
--- a/packages/@aws-cdk/aws-cloudwatch/lib/graph.ts
+++ b/packages/@aws-cdk/aws-cloudwatch/lib/graph.ts
@@ -315,7 +315,7 @@ function metricJson(metric: Metric, yAxis: string): any[] {
     yAxis,
     label: metric.label,
     color: metric.color,
-    period: metric.periodSec,
+    period: metric.period.toSeconds(),
     stat: stat.type === 'simple' ? stat.statistic : 'p' + stat.percentile.toString(),
   });
 
diff --git a/packages/@aws-cdk/aws-cloudwatch/lib/metric.ts b/packages/@aws-cdk/aws-cloudwatch/lib/metric.ts
index da81e2022beda..e18bb750b64f1 100644
--- a/packages/@aws-cdk/aws-cloudwatch/lib/metric.ts
+++ b/packages/@aws-cdk/aws-cloudwatch/lib/metric.ts
@@ -29,11 +29,9 @@ export interface MetricProps {
   /**
    * The period over which the specified statistic is applied.
    *
-   * Specify time in seconds, in multiples of 60.
-   *
-   * @default 300
+   * @default Duration.minutes(5)
    */
-  readonly periodSec?: number;
+  readonly period?: cdk.Duration;
 
   /**
    * What function to use for aggregating.
@@ -98,23 +96,22 @@ export class Metric {
   public readonly dimensions?: DimensionHash;
   public readonly namespace: string;
   public readonly metricName: string;
-  public readonly periodSec: number;
+  public readonly period: cdk.Duration;
   public readonly statistic: string;
   public readonly unit?: Unit;
   public readonly label?: string;
   public readonly color?: string;
 
   constructor(props: MetricProps) {
-    if (props.periodSec !== undefined
-      && props.periodSec !== 1 && props.periodSec !== 5 && props.periodSec !== 10 && props.periodSec !== 30
-      && props.periodSec % 60 !== 0) {
-      throw new Error("'periodSec' must be 1, 5, 10, 30, or a multiple of 60");
+    this.period = props.period || cdk.Duration.minutes(5);
+    const periodSec = this.period.toSeconds();
+    if (periodSec !== 1 && periodSec !== 5 && periodSec !== 10 && periodSec !== 30 && periodSec % 60 !== 0) {
+      throw new Error(`'period' must be 1, 5, 10, 30, or a multiple of 60 seconds, received ${props.period}`);
     }
 
     this.dimensions = props.dimensions;
     this.namespace = props.namespace;
     this.metricName = props.metricName;
-    this.periodSec = props.periodSec !== undefined ? props.periodSec : 300;
     // Try parsing, this will throw if it's not a valid stat
     this.statistic = normalizeStatistic(props.statistic || "Average");
     this.label = props.label;
@@ -134,7 +131,7 @@ export class Metric {
       dimensions: ifUndefined(props.dimensions, this.dimensions),
       namespace: this.namespace,
       metricName: this.metricName,
-      periodSec: ifUndefined(props.periodSec, this.periodSec),
+      period: ifUndefined(props.period, this.period),
       statistic: ifUndefined(props.statistic, this.statistic),
       unit: ifUndefined(props.unit, this.unit),
       label: ifUndefined(props.label, this.label),
@@ -152,7 +149,7 @@ export class Metric {
     return new Alarm(scope, id, {
       metric: this.with({
         statistic: props.statistic,
-        periodSec: props.periodSec,
+        period: props.period,
       }),
       alarmName: props.alarmName,
       alarmDescription: props.alarmDescription,
@@ -255,11 +252,9 @@ export interface MetricOptions {
   /**
    * The period over which the specified statistic is applied.
    *
-   * Specify time in seconds, in multiples of 60.
-   *
-   * @default 300
+   * @default Duration.minutes(5)
    */
-  readonly periodSec?: number;
+  readonly period?: cdk.Duration;
 
   /**
    * What function to use for aggregating.
@@ -300,11 +295,9 @@ export interface MetricAlarmProps {
   /**
    * The period over which the specified statistic is applied.
    *
-   * Specify time in seconds, in multiples of 60.
-   *
-   * @default 300
+   * @default Duration.minutes(5)
    */
-  readonly periodSec?: number;
+  readonly period?: cdk.Duration;
 
   /**
    * What function to use for aggregating.
diff --git a/packages/@aws-cdk/aws-cloudwatch/test/test.alarm.ts b/packages/@aws-cdk/aws-cloudwatch/test/test.alarm.ts
index bb219e2b76f77..3beab9756f2b8 100644
--- a/packages/@aws-cdk/aws-cloudwatch/test/test.alarm.ts
+++ b/packages/@aws-cdk/aws-cloudwatch/test/test.alarm.ts
@@ -1,5 +1,5 @@
 import { expect, haveResource } from '@aws-cdk/assert';
-import { Construct, Stack } from '@aws-cdk/cdk';
+import { Construct, Duration, Stack } from '@aws-cdk/cdk';
 import { Test } from 'nodeunit';
 import { Alarm, IAlarm, IAlarmAction, Metric } from '../lib';
 
@@ -95,7 +95,7 @@ export = {
       threshold: 1000,
       evaluationPeriods: 2,
       statistic: 'min',
-      periodSec: 10,
+      period: Duration.seconds(10),
     });
 
     // THEN
diff --git a/packages/@aws-cdk/aws-codebuild/lib/project.ts b/packages/@aws-cdk/aws-codebuild/lib/project.ts
index 381b2c7c2ffff..d1bbffd04161e 100644
--- a/packages/@aws-cdk/aws-codebuild/lib/project.ts
+++ b/packages/@aws-cdk/aws-codebuild/lib/project.ts
@@ -6,7 +6,7 @@ import ecr = require('@aws-cdk/aws-ecr');
 import events = require('@aws-cdk/aws-events');
 import iam = require('@aws-cdk/aws-iam');
 import kms = require('@aws-cdk/aws-kms');
-import { Aws, Construct, IResource, Lazy, PhysicalName, Resource, ResourceIdentifiers, Stack } from '@aws-cdk/cdk';
+import { Aws, Construct, Duration, IResource, Lazy, PhysicalName, Resource, ResourceIdentifiers, Stack } from '@aws-cdk/cdk';
 import { BuildArtifacts, CodePipelineBuildArtifacts, NoBuildArtifacts } from './artifacts';
 import { Cache } from './cache';
 import { CfnProject } from './codebuild.generated';
@@ -435,9 +435,9 @@ export interface CommonProjectProps {
    * not complete. For valid values, see the timeoutInMinutes field in the AWS
    * CodeBuild User Guide.
    *
-   * @default 60
+   * @default Duration.hours(1)
    */
-  readonly timeout?: number;
+  readonly timeout?: Duration;
 
   /**
    * Additional environment variables to add to the build environment.
@@ -704,7 +704,7 @@ export class Project extends ProjectBase {
       badgeEnabled: props.badge,
       cache: cache._toCloudFormation(),
       name: this.physicalName.value,
-      timeoutInMinutes: props.timeout,
+      timeoutInMinutes: props.timeout && props.timeout.toMinutes(),
       secondarySources: Lazy.anyValue({ produce: () => this.renderSecondarySources() }),
       secondaryArtifacts: Lazy.anyValue({ produce: () => this.renderSecondaryArtifacts() }),
       triggers: this.source._buildTriggers(),
diff --git a/packages/@aws-cdk/aws-codebuild/package.json b/packages/@aws-cdk/aws-codebuild/package.json
index c18b6e2a9eb64..d26383f8ce095 100644
--- a/packages/@aws-cdk/aws-codebuild/package.json
+++ b/packages/@aws-cdk/aws-codebuild/package.json
@@ -108,8 +108,10 @@
   },
   "awslint": {
     "exclude": [
-      "construct-ctor-props-optional:@aws-cdk/aws-codebuild.Project"
+      "construct-ctor-props-optional:@aws-cdk/aws-codebuild.Project",
+      "duration-prop-type:@aws-cdk/aws-codebuild.PhaseChangeEvent.completedPhaseDurationSeconds",
+      "duration-prop-name:@aws-cdk/aws-codebuild.PhaseChangeEvent.completedPhaseDurationSeconds"
     ]
   },
   "stability": "experimental"
-}
\ No newline at end of file
+}
diff --git a/packages/@aws-cdk/aws-codebuild/test/test.codebuild.ts b/packages/@aws-cdk/aws-codebuild/test/test.codebuild.ts
index 9badd9435488e..5ea4d04dcae64 100644
--- a/packages/@aws-cdk/aws-codebuild/test/test.codebuild.ts
+++ b/packages/@aws-cdk/aws-codebuild/test/test.codebuild.ts
@@ -770,7 +770,7 @@ export = {
         name: 'some_name',
         bucket,
       }),
-      timeout: 123,
+      timeout: cdk.Duration.minutes(123),
     });
 
     expect(stack).to(haveResourceLike('AWS::CodeBuild::Project', {
diff --git a/packages/@aws-cdk/aws-config/lib/managed-rules.ts b/packages/@aws-cdk/aws-config/lib/managed-rules.ts
index d6f6947128e03..e1d72bc935a9c 100644
--- a/packages/@aws-cdk/aws-config/lib/managed-rules.ts
+++ b/packages/@aws-cdk/aws-config/lib/managed-rules.ts
@@ -1,6 +1,6 @@
 import iam = require('@aws-cdk/aws-iam');
 import sns = require('@aws-cdk/aws-sns');
-import { Construct, Lazy, Stack } from '@aws-cdk/cdk';
+import { Construct, Duration, Lazy, Stack } from '@aws-cdk/cdk';
 import { ManagedRule, RuleProps } from './rule';
 
 /**
@@ -10,14 +10,14 @@ export interface AccessKeysRotatedProps extends RuleProps {
   /**
    * The maximum number of days within which the access keys must be rotated.
    *
-   * @default 90 days
+   * @default Duration.days(90)
    */
-  readonly maxDays?: number;
+  readonly maxAge?: Duration;
 }
 
 /**
  * Checks whether the active access keys are rotated within the number of days
- * specified in `maxDays`.
+ * specified in `maxAge`.
  *
  * @see https://docs.aws.amazon.com/config/latest/developerguide/access-keys-rotated.html
  *
@@ -29,9 +29,9 @@ export class AccessKeysRotated extends ManagedRule {
       ...props,
       identifier: 'ACCESS_KEYS_ROTATED',
       inputParameters: {
-        ...props.maxDays
+        ...props.maxAge
           ? {
-              maxAccessKeyAge: props.maxDays
+              maxAccessKeyAge: props.maxAge.toDays()
             }
           : {}
         }
diff --git a/packages/@aws-cdk/aws-dynamodb-global/lib/global-table-coordinator.ts b/packages/@aws-cdk/aws-dynamodb-global/lib/global-table-coordinator.ts
index 5747247d6d1b9..e9ffd05337278 100644
--- a/packages/@aws-cdk/aws-dynamodb-global/lib/global-table-coordinator.ts
+++ b/packages/@aws-cdk/aws-dynamodb-global/lib/global-table-coordinator.ts
@@ -17,7 +17,7 @@ export class GlobalTableCoordinator extends cdk.Stack {
       description: "Lambda to make DynamoDB a global table",
       handler: "index.handler",
       runtime: lambda.Runtime.NodeJS810,
-      timeout: 300,
+      timeout: cdk.Duration.minutes(5),
       uuid: "D38B65A6-6B54-4FB6-9BAD-9CD40A6DAC12",
     });
 
diff --git a/packages/@aws-cdk/aws-dynamodb/lib/scalable-table-attribute.ts b/packages/@aws-cdk/aws-dynamodb/lib/scalable-table-attribute.ts
index a0fb5e83bf946..cf95747f7768f 100644
--- a/packages/@aws-cdk/aws-dynamodb/lib/scalable-table-attribute.ts
+++ b/packages/@aws-cdk/aws-dynamodb/lib/scalable-table-attribute.ts
@@ -27,8 +27,8 @@ export class ScalableTableAttribute extends appscaling.BaseScalableAttribute {
     super.doScaleToTrackMetric('Tracking', {
       policyName: props.policyName,
       disableScaleIn: props.disableScaleIn,
-      scaleInCooldownSec: props.scaleInCooldownSec,
-      scaleOutCooldownSec: props.scaleOutCooldownSec,
+      scaleInCooldown: props.scaleInCooldown,
+      scaleOutCooldown: props.scaleOutCooldown,
       targetValue: props.targetUtilizationPercent,
       predefinedMetric,
     });
diff --git a/packages/@aws-cdk/aws-ec2/test/test.vpn.ts b/packages/@aws-cdk/aws-ec2/test/test.vpn.ts
index 97e6c321ec56d..5e805f6d04c37 100644
--- a/packages/@aws-cdk/aws-ec2/test/test.vpn.ts
+++ b/packages/@aws-cdk/aws-ec2/test/test.vpn.ts
@@ -1,5 +1,5 @@
 import { expect, haveResource,  } from '@aws-cdk/assert';
-import { Stack } from '@aws-cdk/cdk';
+import { Duration, Stack } from '@aws-cdk/cdk';
 import { Test } from 'nodeunit';
 import { Vpc, VpnConnection } from '../lib';
 
@@ -278,7 +278,7 @@ export = {
       dimensions: { VpnId: { Ref: 'VpcNetworkVpnA476C58D' } },
       namespace: 'AWS/VPN',
       metricName: 'TunnelState',
-      periodSec: 300,
+      period: Duration.minutes(5),
       statistic: 'Average'
     });
 
@@ -293,7 +293,7 @@ export = {
     test.deepEqual(stack.resolve(VpnConnection.metricAllTunnelDataOut()), {
       namespace: 'AWS/VPN',
       metricName: 'TunnelDataOut',
-      periodSec: 300,
+      period: Duration.minutes(5),
       statistic: 'Sum'
     });
 
diff --git a/packages/@aws-cdk/aws-ecr/lib/lifecycle.ts b/packages/@aws-cdk/aws-ecr/lib/lifecycle.ts
index d86bb540c7e7b..3fba6351941f0 100644
--- a/packages/@aws-cdk/aws-ecr/lib/lifecycle.ts
+++ b/packages/@aws-cdk/aws-ecr/lib/lifecycle.ts
@@ -1,3 +1,5 @@
+import { Duration } from '@aws-cdk/cdk';
+
 /**
  * An ECR life cycle rule
  */
@@ -50,11 +52,11 @@ export interface LifecycleRule {
   readonly maxImageCount?: number;
 
   /**
-   * The maximum age of images to retain
+   * The maximum age of images to retain. The value must represent a number of days.
    *
-   * Specify exactly one of maxImageCount and maxImageAgeDays.
+   * Specify exactly one of maxImageCount and maxImageAge.
    */
-  readonly maxImageAgeDays?: number;
+  readonly maxImageAge?: Duration;
 }
 
 /**
diff --git a/packages/@aws-cdk/aws-ecr/lib/repository.ts b/packages/@aws-cdk/aws-ecr/lib/repository.ts
index 9fa3186fedf3a..ec56b729cf3f2 100644
--- a/packages/@aws-cdk/aws-ecr/lib/repository.ts
+++ b/packages/@aws-cdk/aws-ecr/lib/repository.ts
@@ -385,8 +385,8 @@ export class Repository extends RepositoryBase {
     if (rule.tagStatus !== TagStatus.Tagged && rule.tagPrefixList !== undefined) {
       throw new Error('tagPrefixList can only be specified when tagStatus is set to Tagged');
     }
-    if ((rule.maxImageAgeDays !== undefined) === (rule.maxImageCount !== undefined)) {
-      throw new Error(`Life cycle rule must contain exactly one of 'maxImageAgeDays' and 'maxImageCount', got: ${JSON.stringify(rule)}`);
+    if ((rule.maxImageAge !== undefined) === (rule.maxImageCount !== undefined)) {
+      throw new Error(`Life cycle rule must contain exactly one of 'maxImageAge' and 'maxImageCount', got: ${JSON.stringify(rule)}`);
     }
 
     if (rule.tagStatus === TagStatus.Any && this.lifecycleRules.filter(r => r.tagStatus === TagStatus.Any).length > 0) {
@@ -470,9 +470,9 @@ function renderLifecycleRule(rule: LifecycleRule) {
     selection: {
       tagStatus: rule.tagStatus || TagStatus.Any,
       tagPrefixList: rule.tagPrefixList,
-      countType: rule.maxImageAgeDays !== undefined ? CountType.SinceImagePushed : CountType.ImageCountMoreThan,
-      countNumber: rule.maxImageAgeDays !== undefined ? rule.maxImageAgeDays : rule.maxImageCount,
-      countUnit: rule.maxImageAgeDays !== undefined ? 'days' : undefined,
+      countType: rule.maxImageAge !== undefined ? CountType.SinceImagePushed : CountType.ImageCountMoreThan,
+      countNumber: rule.maxImageAge !== undefined ? rule.maxImageAge.toDays() : rule.maxImageCount,
+      countUnit: rule.maxImageAge !== undefined ? 'days' : undefined,
     },
     action: {
       type: 'expire'
diff --git a/packages/@aws-cdk/aws-ecr/test/test.repository.ts b/packages/@aws-cdk/aws-ecr/test/test.repository.ts
index ebbaf4aa44504..8affb900c9275 100644
--- a/packages/@aws-cdk/aws-ecr/test/test.repository.ts
+++ b/packages/@aws-cdk/aws-ecr/test/test.repository.ts
@@ -52,7 +52,7 @@ export = {
     // WHEN
     const repo = new ecr.Repository(stack, 'Repo');
     repo.addLifecycleRule({
-      maxImageAgeDays: 5,
+      maxImageAge: cdk.Duration.days(5),
     });
 
     // THEN
diff --git a/packages/@aws-cdk/aws-ecs/lib/base/base-service.ts b/packages/@aws-cdk/aws-ecs/lib/base/base-service.ts
index ff2c41da4eaa8..423f048993954 100644
--- a/packages/@aws-cdk/aws-ecs/lib/base/base-service.ts
+++ b/packages/@aws-cdk/aws-ecs/lib/base/base-service.ts
@@ -4,8 +4,7 @@ import ec2 = require('@aws-cdk/aws-ec2');
 import elbv2 = require('@aws-cdk/aws-elasticloadbalancingv2');
 import iam = require('@aws-cdk/aws-iam');
 import cloudmap = require('@aws-cdk/aws-servicediscovery');
-import { IResource, Lazy, Resource, Stack } from '@aws-cdk/cdk';
-import cdk = require('@aws-cdk/cdk');
+import { Construct, Duration, Fn, IResource, Lazy, Resource, Stack, toSeconds } from '@aws-cdk/cdk';
 import { NetworkMode, TaskDefinition } from '../base/task-definition';
 import { ICluster } from '../cluster';
 import { CfnService } from '../ecs.generated';
@@ -66,7 +65,7 @@ export interface BaseServiceProps {
    *
    * @default ??? FIXME
    */
-  readonly healthCheckGracePeriodSeconds?: number;
+  readonly healthCheckGracePeriod?: Duration;
 
   /**
    * Options for enabling AWS Cloud Map service discovery for the service
@@ -133,7 +132,7 @@ export abstract class BaseService extends Resource
   private readonly resource: CfnService;
   private scalableTaskCount?: ScalableTaskCount;
 
-  constructor(scope: cdk.Construct,
+  constructor(scope: Construct,
               id: string,
               props: BaseServiceProps,
               additionalProps: any,
@@ -151,7 +150,7 @@ export abstract class BaseService extends Resource
         maximumPercent: props.maximumPercent || 200,
         minimumHealthyPercent: props.minimumHealthyPercent === undefined ? 50 : props.minimumHealthyPercent
       },
-      healthCheckGracePeriodSeconds: props.healthCheckGracePeriodSeconds,
+      healthCheckGracePeriodSeconds: toSeconds(props.healthCheckGracePeriod),
       /* role: never specified, supplanted by Service Linked Role */
       networkConfiguration: Lazy.anyValue({ produce: () => this.networkConfiguration }),
       serviceRegistries: Lazy.anyValue({ produce: () => this.serviceRegistries }),
@@ -164,7 +163,7 @@ export abstract class BaseService extends Resource
     // are enabled for the principal in a given region.
     const longArnEnabled = props.longArnEnabled !== undefined ? props.longArnEnabled : false;
     this.serviceName = longArnEnabled
-      ? cdk.Fn.select(2, cdk.Fn.split('/', this.serviceArn))
+      ? Fn.select(2, Fn.split('/', this.serviceArn))
       : this.resource.serviceName;
 
     this.clusterName = clusterName;
@@ -411,7 +410,7 @@ export interface ServiceDiscoveryOptions {
    *
    * @default 60
    */
-  readonly dnsTtlSec?: number;
+  readonly dnsTtl?: Duration;
 
   /**
    * The number of 30-second intervals that you want Cloud Map to wait after receiving an
diff --git a/packages/@aws-cdk/aws-ecs/lib/base/scalable-task-count.ts b/packages/@aws-cdk/aws-ecs/lib/base/scalable-task-count.ts
index 54a7c5e80fa2e..73fccecfa3940 100644
--- a/packages/@aws-cdk/aws-ecs/lib/base/scalable-task-count.ts
+++ b/packages/@aws-cdk/aws-ecs/lib/base/scalable-task-count.ts
@@ -40,8 +40,8 @@ export class ScalableTaskCount extends appscaling.BaseScalableAttribute {
       policyName: props.policyName,
       disableScaleIn: props.disableScaleIn,
       targetValue: props.targetUtilizationPercent,
-      scaleInCooldownSec: props.scaleInCooldownSec,
-      scaleOutCooldownSec: props.scaleOutCooldownSec
+      scaleInCooldown: props.scaleInCooldown,
+      scaleOutCooldown: props.scaleOutCooldown
     });
   }
 
@@ -54,8 +54,8 @@ export class ScalableTaskCount extends appscaling.BaseScalableAttribute {
       targetValue: props.targetUtilizationPercent,
       policyName: props.policyName,
       disableScaleIn: props.disableScaleIn,
-      scaleInCooldownSec: props.scaleInCooldownSec,
-      scaleOutCooldownSec: props.scaleOutCooldownSec
+      scaleInCooldown: props.scaleInCooldown,
+      scaleOutCooldown: props.scaleOutCooldown
     });
   }
 
@@ -72,8 +72,8 @@ export class ScalableTaskCount extends appscaling.BaseScalableAttribute {
       targetValue: props.requestsPerTarget,
       policyName: props.policyName,
       disableScaleIn: props.disableScaleIn,
-      scaleInCooldownSec: props.scaleInCooldownSec,
-      scaleOutCooldownSec: props.scaleOutCooldownSec
+      scaleInCooldown: props.scaleInCooldown,
+      scaleOutCooldown: props.scaleOutCooldown
     });
   }
 
@@ -86,8 +86,8 @@ export class ScalableTaskCount extends appscaling.BaseScalableAttribute {
       targetValue: props.targetValue,
       policyName: props.policyName,
       disableScaleIn: props.disableScaleIn,
-      scaleInCooldownSec: props.scaleInCooldownSec,
-      scaleOutCooldownSec: props.scaleOutCooldownSec,
+      scaleInCooldown: props.scaleInCooldown,
+      scaleOutCooldown: props.scaleOutCooldown,
     });
   }
 }
diff --git a/packages/@aws-cdk/aws-ecs/lib/cluster.ts b/packages/@aws-cdk/aws-ecs/lib/cluster.ts
index cf9812bbe887a..2c5d2d90d6723 100644
--- a/packages/@aws-cdk/aws-ecs/lib/cluster.ts
+++ b/packages/@aws-cdk/aws-ecs/lib/cluster.ts
@@ -3,7 +3,7 @@ import cloudwatch = require ('@aws-cdk/aws-cloudwatch');
 import ec2 = require('@aws-cdk/aws-ec2');
 import iam = require('@aws-cdk/aws-iam');
 import cloudmap = require('@aws-cdk/aws-servicediscovery');
-import { Construct, IResource, Resource, SSMParameterProvider, Stack } from '@aws-cdk/cdk';
+import { Construct, Duration, IResource, Resource, SSMParameterProvider, Stack } from '@aws-cdk/cdk';
 import { InstanceDrainHook } from './drain-hook/instance-drain-hook';
 import { CfnCluster } from './ecs.generated';
 
@@ -167,11 +167,11 @@ export class Cluster extends Resource implements ICluster {
     ).addAllResources());
 
     // 0 disables, otherwise forward to underlying implementation which picks the sane default
-    if (options.taskDrainTimeSeconds !== 0) {
+    if (!options.taskDrainTime || options.taskDrainTime.toSeconds() !== 0) {
       new InstanceDrainHook(autoScalingGroup, 'DrainECSHook', {
         autoScalingGroup,
         cluster: this,
-        drainTimeSec: options.taskDrainTimeSeconds
+        drainTime: options.taskDrainTime
       });
     }
   }
@@ -442,9 +442,9 @@ export interface AddAutoScalingGroupCapacityOptions {
    *
    * Set to 0 to disable task draining.
    *
-   * @default 300
+   * @default Duration.minutes(5)
    */
-  readonly taskDrainTimeSeconds?: number;
+  readonly taskDrainTime?: Duration;
 }
 
 /**
diff --git a/packages/@aws-cdk/aws-ecs/lib/container-definition.ts b/packages/@aws-cdk/aws-ecs/lib/container-definition.ts
index d05de2d082f62..daca16ee46e25 100644
--- a/packages/@aws-cdk/aws-ecs/lib/container-definition.ts
+++ b/packages/@aws-cdk/aws-ecs/lib/container-definition.ts
@@ -434,9 +434,9 @@ export interface HealthCheck {
    *
    * You may specify between 5 and 300 seconds.
    *
-   * @default 30
+   * @default Duration.seconds(30)
    */
-  readonly intervalSeconds?: number;
+  readonly interval?: cdk.Duration;
 
   /**
    * Number of times to retry a failed health check before the container is considered unhealthy.
@@ -454,16 +454,16 @@ export interface HealthCheck {
    *
    * @default No start period
    */
-  readonly startPeriod?: number;
+  readonly startPeriod?: cdk.Duration;
 
   /**
    * The time period in seconds to wait for a health check to succeed before it is considered a failure.
    *
    * You may specify between 2 and 60 seconds.
    *
-   * @default 5
+   * @default Duration.seconds(5)
    */
-  readonly timeout?: number;
+  readonly timeout?: cdk.Duration;
 }
 
 function renderKV(env: { [key: string]: string }, keyName: string, valueName: string): any {
@@ -477,10 +477,10 @@ function renderKV(env: { [key: string]: string }, keyName: string, valueName: st
 function renderHealthCheck(hc: HealthCheck): CfnTaskDefinition.HealthCheckProperty {
   return {
     command: getHealthCheckCommand(hc),
-    interval: hc.intervalSeconds !== undefined ? hc.intervalSeconds : 30,
+    interval: hc.interval != null ? hc.interval.toSeconds() : 30,
     retries: hc.retries !== undefined ? hc.retries : 3,
-    startPeriod: hc.startPeriod,
-    timeout: hc.timeout !== undefined ? hc.timeout : 5,
+    startPeriod: cdk.toSeconds(hc.startPeriod),
+    timeout: hc.timeout !== undefined ? hc.timeout.toSeconds() : 5,
   };
 }
 
diff --git a/packages/@aws-cdk/aws-ecs/lib/drain-hook/instance-drain-hook.ts b/packages/@aws-cdk/aws-ecs/lib/drain-hook/instance-drain-hook.ts
index 87fd362a0eccb..83434861e5e1d 100644
--- a/packages/@aws-cdk/aws-ecs/lib/drain-hook/instance-drain-hook.ts
+++ b/packages/@aws-cdk/aws-ecs/lib/drain-hook/instance-drain-hook.ts
@@ -28,11 +28,11 @@ export interface InstanceDrainHookProps {
   /**
    * How many seconds to give tasks to drain before the instance is terminated anyway
    *
-   * Must be between 0 and 900.
+   * Must be between 0 and 15 minutes.
    *
-   * @default 900
+   * @default Duration.minutes(15)
    */
-  drainTimeSec?: number;
+  drainTime?: cdk.Duration;
 }
 
 /**
@@ -42,11 +42,7 @@ export class InstanceDrainHook extends cdk.Construct {
   constructor(scope: cdk.Construct, id: string, props: InstanceDrainHookProps) {
     super(scope, id);
 
-    const drainTimeSeconds = props.drainTimeSec !== undefined ? props.drainTimeSec : 300;
-
-    if (drainTimeSeconds < 0 || drainTimeSeconds > 900) {
-      throw new Error(`Drain time must be between 0 and 900 seconds, got: ${drainTimeSeconds}`);
-    }
+    const drainTime = props.drainTime || cdk.Duration.minutes(5);
 
     // Invoke Lambda via SNS Topic
     const fn = new lambda.Function(this, 'Function', {
@@ -55,7 +51,7 @@ export class InstanceDrainHook extends cdk.Construct {
       runtime: lambda.Runtime.Python36,
       // Timeout: some extra margin for additional API calls made by the Lambda,
       // up to a maximum of 15 minutes.
-      timeout: Math.min(drainTimeSeconds + 10, 900),
+      timeout: cdk.Duration.seconds(Math.min(drainTime.toSeconds() + 10, 900)),
       environment: {
         CLUSTER: props.cluster.clusterName
       }
@@ -66,7 +62,7 @@ export class InstanceDrainHook extends cdk.Construct {
       lifecycleTransition: autoscaling.LifecycleTransition.InstanceTerminating,
       defaultResult: autoscaling.DefaultResult.Continue,
       notificationTarget: new hooks.FunctionHook(fn),
-      heartbeatTimeoutSec: drainTimeSeconds,
+      heartbeatTimeout: drainTime,
     });
 
     // FIXME: These should probably be restricted usefully in some way, but I don't exactly
diff --git a/packages/@aws-cdk/aws-ecs/lib/log-drivers/aws-log-driver.ts b/packages/@aws-cdk/aws-ecs/lib/log-drivers/aws-log-driver.ts
index b21e77d74ccc0..2c752ba0ad1ea 100644
--- a/packages/@aws-cdk/aws-ecs/lib/log-drivers/aws-log-driver.ts
+++ b/packages/@aws-cdk/aws-ecs/lib/log-drivers/aws-log-driver.ts
@@ -34,7 +34,7 @@ export interface AwsLogDriverProps {
    *
    * @default - Logs never expire.
    */
-  readonly logRetentionDays?: logs.RetentionDays;
+  readonly logRetention?: logs.RetentionDays;
 
   /**
    * This option defines a multiline start pattern in Python strftime format.
@@ -73,12 +73,12 @@ export class AwsLogDriver extends LogDriver {
   constructor(scope: cdk.Construct, id: string, private readonly props: AwsLogDriverProps) {
     super(scope, id);
 
-    if (props.logGroup && props.logRetentionDays) {
+    if (props.logGroup && props.logRetention) {
       throw new Error('Cannot specify both `logGroup` and `logRetentionDays`.');
     }
 
     this.logGroup = props.logGroup || new logs.LogGroup(this, 'LogGroup', {
-        retentionDays: props.logRetentionDays || Infinity,
+        retention: props.logRetention || Infinity,
     });
   }
 
diff --git a/packages/@aws-cdk/aws-ecs/test/ec2/test.ec2-service.ts b/packages/@aws-cdk/aws-ecs/test/ec2/test.ec2-service.ts
index 891d3592325bc..80228781b1665 100644
--- a/packages/@aws-cdk/aws-ecs/test/ec2/test.ec2-service.ts
+++ b/packages/@aws-cdk/aws-ecs/test/ec2/test.ec2-service.ts
@@ -1034,7 +1034,7 @@ export = {
       },
       namespace: 'AWS/ECS',
       metricName: 'MemoryUtilization',
-      periodSec: 300,
+      period: cdk.Duration.minutes(5),
       statistic: 'Average'
     });
 
diff --git a/packages/@aws-cdk/aws-ecs/test/fargate/test.fargate-service.ts b/packages/@aws-cdk/aws-ecs/test/fargate/test.fargate-service.ts
index 16950b85d80ef..cfe58d85319a9 100644
--- a/packages/@aws-cdk/aws-ecs/test/fargate/test.fargate-service.ts
+++ b/packages/@aws-cdk/aws-ecs/test/fargate/test.fargate-service.ts
@@ -174,7 +174,7 @@ export = {
       new ecs.FargateService(stack, 'Svc', {
         cluster,
         taskDefinition,
-        healthCheckGracePeriodSeconds: 10
+        healthCheckGracePeriod: cdk.Duration.seconds(10)
       });
 
       // THEN
@@ -493,7 +493,7 @@ export = {
       },
       namespace: 'AWS/ECS',
       metricName: 'CPUUtilization',
-      periodSec: 300,
+      period: cdk.Duration.minutes(5),
       statistic: 'Average'
     });
 
diff --git a/packages/@aws-cdk/aws-ecs/test/test.aws-log-driver.ts b/packages/@aws-cdk/aws-ecs/test/test.aws-log-driver.ts
index 159205c50d31b..71a54e03301a5 100644
--- a/packages/@aws-cdk/aws-ecs/test/test.aws-log-driver.ts
+++ b/packages/@aws-cdk/aws-ecs/test/test.aws-log-driver.ts
@@ -12,7 +12,7 @@ export = {
     // WHEN
     const driver = new ecs.AwsLogDriver(stack, 'Log', {
       datetimeFormat: 'format',
-      logRetentionDays: logs.RetentionDays.OneMonth,
+      logRetention: logs.RetentionDays.OneMonth,
       multilinePattern: 'pattern',
       streamPrefix: 'hello'
     });
@@ -74,7 +74,7 @@ export = {
     // THEN
     test.throws(() => new ecs.AwsLogDriver(stack, 'Log', {
       logGroup,
-      logRetentionDays: logs.RetentionDays.FiveDays,
+      logRetention: logs.RetentionDays.FiveDays,
       streamPrefix: 'hello'
     }), /`logGroup`.*`logRetentionDays`/);
 
diff --git a/packages/@aws-cdk/aws-ecs/test/test.container-definition.ts b/packages/@aws-cdk/aws-ecs/test/test.container-definition.ts
index e0661b909e510..13c0e03d70bfa 100644
--- a/packages/@aws-cdk/aws-ecs/test/test.container-definition.ts
+++ b/packages/@aws-cdk/aws-ecs/test/test.container-definition.ts
@@ -372,9 +372,9 @@ export = {
       memoryLimitMiB: 1024,
       healthCheck: {
         command: [hcCommand],
-        intervalSeconds: 20,
+        interval: cdk.Duration.seconds(20),
         retries: 5,
-        startPeriod: 10
+        startPeriod: cdk.Duration.seconds(10)
       }
     });
 
@@ -408,9 +408,9 @@ export = {
       memoryLimitMiB: 1024,
       healthCheck: {
         command: ["CMD-SHELL", hcCommand],
-        intervalSeconds: 20,
+        interval: cdk.Duration.seconds(20),
         retries: 5,
-        startPeriod: 10
+        startPeriod: cdk.Duration.seconds(10)
       }
     });
 
@@ -444,9 +444,9 @@ export = {
       memoryLimitMiB: 1024,
       healthCheck: {
         command: ["CMD", hcCommand],
-        intervalSeconds: 20,
+        interval: cdk.Duration.seconds(20),
         retries: 5,
-        startPeriod: 10
+        startPeriod: cdk.Duration.seconds(10)
       }
     });
 
diff --git a/packages/@aws-cdk/aws-elasticloadbalancing/lib/load-balancer.ts b/packages/@aws-cdk/aws-elasticloadbalancing/lib/load-balancer.ts
index fad3d826d81fc..ed969cfb1b243 100644
--- a/packages/@aws-cdk/aws-elasticloadbalancing/lib/load-balancer.ts
+++ b/packages/@aws-cdk/aws-elasticloadbalancing/lib/load-balancer.ts
@@ -1,7 +1,7 @@
 import {
   AnyIPv4, Connections, IConnectable, IPortRange, ISecurityGroup,
   ISubnet, IVpc, SecurityGroup, TcpPort  } from '@aws-cdk/aws-ec2';
-import { Construct, Lazy, Resource } from '@aws-cdk/cdk';
+import { Construct, Duration, Lazy, Resource } from '@aws-cdk/cdk';
 import { CfnLoadBalancer } from './elasticloadbalancing.generated';
 
 /**
@@ -96,16 +96,16 @@ export interface HealthCheck {
   /**
    * Number of seconds between health checks
    *
-   * @default 30
+   * @default Duration.seconds(30)
    */
-  readonly interval?: number;
+  readonly interval?: Duration;
 
   /**
    * Health check timeout
    *
-   * @default 5
+   * @default Duration.seconds(5)
    */
-  readonly timeout?: number;
+  readonly timeout?: Duration;
 }
 
 /**
@@ -411,9 +411,9 @@ function healthCheckToJSON(healthCheck: HealthCheck): CfnLoadBalancer.HealthChec
 
   return {
     healthyThreshold: ifUndefined(healthCheck.healthyThreshold, 2).toString(),
-    interval: ifUndefined(healthCheck.interval, 30).toString(),
+    interval: (healthCheck.interval || Duration.seconds(30)).toSeconds().toString(),
     target,
-    timeout: ifUndefined(healthCheck.timeout, 5).toString(),
+    timeout: (healthCheck.timeout || Duration.seconds(5)).toSeconds().toString(),
     unhealthyThreshold: ifUndefined(healthCheck.unhealthyThreshold, 5).toString(),
   };
 }
diff --git a/packages/@aws-cdk/aws-elasticloadbalancing/test/test.loadbalancer.ts b/packages/@aws-cdk/aws-elasticloadbalancing/test/test.loadbalancer.ts
index 96c94a973def7..4f649756ba638 100644
--- a/packages/@aws-cdk/aws-elasticloadbalancing/test/test.loadbalancer.ts
+++ b/packages/@aws-cdk/aws-elasticloadbalancing/test/test.loadbalancer.ts
@@ -1,6 +1,6 @@
 import { expect, haveResource } from '@aws-cdk/assert';
 import { CidrIPv4, Connections, Vpc } from '@aws-cdk/aws-ec2';
-import { Stack } from '@aws-cdk/cdk';
+import { Duration, Stack } from '@aws-cdk/cdk';
 import { Test } from 'nodeunit';
 import { ILoadBalancerTarget, LoadBalancer, LoadBalancingProtocol } from '../lib';
 
@@ -40,7 +40,7 @@ export = {
     new LoadBalancer(stack, 'LB', {
       vpc,
       healthCheck: {
-        interval: 60,
+        interval: Duration.minutes(1),
         path: '/ping',
         protocol: LoadBalancingProtocol.Https,
         port: 443,
@@ -68,7 +68,7 @@ export = {
     const elb = new LoadBalancer(stack, 'LB', {
       vpc,
       healthCheck: {
-        interval: 60,
+        interval: Duration.minutes(1),
         path: '/ping',
         protocol: LoadBalancingProtocol.Https,
         port: 443,
diff --git a/packages/@aws-cdk/aws-elasticloadbalancingv2/lib/alb/application-listener.ts b/packages/@aws-cdk/aws-elasticloadbalancingv2/lib/alb/application-listener.ts
index adb38a833cffc..ed7c60a8d2c5b 100644
--- a/packages/@aws-cdk/aws-elasticloadbalancingv2/lib/alb/application-listener.ts
+++ b/packages/@aws-cdk/aws-elasticloadbalancingv2/lib/alb/application-listener.ts
@@ -1,5 +1,5 @@
 import ec2 = require('@aws-cdk/aws-ec2');
-import { Construct, IResource, Lazy, Resource } from '@aws-cdk/cdk';
+import { Construct, Duration, IResource, Lazy, Resource } from '@aws-cdk/cdk';
 import { BaseListener } from '../shared/base-listener';
 import { HealthCheck } from '../shared/base-target-group';
 import { ApplicationProtocol, SslPolicy } from '../shared/enums';
@@ -190,12 +190,12 @@ export class ApplicationListener extends BaseListener implements IApplicationLis
     }
 
     const group = new ApplicationTargetGroup(this, id + 'Group', {
-      deregistrationDelaySec: props.deregistrationDelaySec,
+      deregistrationDelay: props.deregistrationDelay,
       healthCheck: props.healthCheck,
       port: props.port,
       protocol: props.protocol,
-      slowStartSec: props.slowStartSec,
-      stickinessCookieDurationSec: props.stickinessCookieDurationSec,
+      slowStart: props.slowStart,
+      stickinessCookieDuration: props.stickinessCookieDuration,
       targetGroupName: props.targetGroupName,
       targets: props.targets,
       vpc: this.loadBalancer.vpc,
@@ -491,11 +491,11 @@ export interface AddApplicationTargetsProps extends AddRuleProps {
    * The time period during which the load balancer sends a newly registered
    * target a linearly increasing share of the traffic to the target group.
    *
-   * The range is 30–900 seconds (15 minutes).
+   * The range is 30-900 seconds (15 minutes).
    *
    * @default 0
    */
-  readonly slowStartSec?: number;
+  readonly slowStart?: Duration;
 
   /**
    * The stickiness cookie expiration period.
@@ -505,9 +505,9 @@ export interface AddApplicationTargetsProps extends AddRuleProps {
    * After this period, the cookie is considered stale. The minimum value is
    * 1 second and the maximum value is 7 days (604800 seconds).
    *
-   * @default 86400 (1 day)
+   * @default Duration.days(1)
    */
-  readonly stickinessCookieDurationSec?: number;
+  readonly stickinessCookieDuration?: Duration;
 
   /**
    * The targets to add to this target group.
@@ -532,11 +532,11 @@ export interface AddApplicationTargetsProps extends AddRuleProps {
   /**
    * The amount of time for Elastic Load Balancing to wait before deregistering a target.
    *
-   * The range is 0–3600 seconds.
+   * The range is 0-3600 seconds.
    *
-   * @default 300
+   * @default Duration.minutes(5)
    */
-  readonly deregistrationDelaySec?: number;
+  readonly deregistrationDelay?: Duration;
 
   /**
    * Health check configuration
diff --git a/packages/@aws-cdk/aws-elasticloadbalancingv2/lib/alb/application-load-balancer.ts b/packages/@aws-cdk/aws-elasticloadbalancingv2/lib/alb/application-load-balancer.ts
index 023dd5686c155..9531a07183f30 100644
--- a/packages/@aws-cdk/aws-elasticloadbalancingv2/lib/alb/application-load-balancer.ts
+++ b/packages/@aws-cdk/aws-elasticloadbalancingv2/lib/alb/application-load-balancer.ts
@@ -2,7 +2,7 @@ import cloudwatch = require('@aws-cdk/aws-cloudwatch');
 import ec2 = require('@aws-cdk/aws-ec2');
 import iam = require('@aws-cdk/aws-iam');
 import s3 = require('@aws-cdk/aws-s3');
-import { Construct, Lazy, Resource, Stack } from '@aws-cdk/cdk';
+import { Construct, Duration, Lazy, Resource, Stack } from '@aws-cdk/cdk';
 import { BaseLoadBalancer, BaseLoadBalancerProps, ILoadBalancerV2 } from '../shared/base-load-balancer';
 import { IpAddressType } from '../shared/enums';
 import { ApplicationListener, BaseApplicationListenerProps } from './application-listener';
@@ -39,7 +39,7 @@ export interface ApplicationLoadBalancerProps extends BaseLoadBalancerProps {
    *
    * @default 60
    */
-  readonly idleTimeoutSecs?: number;
+  readonly idleTimeout?: Duration;
 }
 
 /**
@@ -75,7 +75,7 @@ export class ApplicationLoadBalancer extends BaseLoadBalancer implements IApplic
     this.connections = new ec2.Connections({ securityGroups: [this.securityGroup] });
 
     if (props.http2Enabled === false) { this.setAttribute('routing.http2.enabled', 'false'); }
-    if (props.idleTimeoutSecs !== undefined) { this.setAttribute('idle_timeout.timeout_seconds', props.idleTimeoutSecs.toString()); }
+    if (props.idleTimeout !== undefined) { this.setAttribute('idle_timeout.timeout_seconds', props.idleTimeout.toSeconds().toString()); }
   }
 
   /**
diff --git a/packages/@aws-cdk/aws-elasticloadbalancingv2/lib/alb/application-target-group.ts b/packages/@aws-cdk/aws-elasticloadbalancingv2/lib/alb/application-target-group.ts
index 8df988f15f5a8..0bc5be5b55a40 100644
--- a/packages/@aws-cdk/aws-elasticloadbalancingv2/lib/alb/application-target-group.ts
+++ b/packages/@aws-cdk/aws-elasticloadbalancingv2/lib/alb/application-target-group.ts
@@ -1,6 +1,6 @@
 import cloudwatch = require('@aws-cdk/aws-cloudwatch');
 import ec2 = require('@aws-cdk/aws-ec2');
-import { Construct, IConstruct } from '@aws-cdk/cdk';
+import { Construct, Duration, IConstruct } from '@aws-cdk/cdk';
 import { BaseTargetGroupProps, ITargetGroup, loadBalancerNameFromListenerArn, LoadBalancerTargetProps,
          TargetGroupBase, TargetGroupImportProps } from '../shared/base-target-group';
 import { ApplicationProtocol } from '../shared/enums';
@@ -31,11 +31,11 @@ export interface ApplicationTargetGroupProps extends BaseTargetGroupProps {
    * The time period during which the load balancer sends a newly registered
    * target a linearly increasing share of the traffic to the target group.
    *
-   * The range is 30–900 seconds (15 minutes).
+   * The range is 30-900 seconds (15 minutes).
    *
    * @default 0
    */
-  readonly slowStartSec?: number;
+  readonly slowStart?: Duration;
 
   /**
    * The stickiness cookie expiration period.
@@ -45,9 +45,9 @@ export interface ApplicationTargetGroupProps extends BaseTargetGroupProps {
    * After this period, the cookie is considered stale. The minimum value is
    * 1 second and the maximum value is 7 days (604800 seconds).
    *
-   * @default 86400 (1 day)
+   * @default Duration.days(1)
    */
-  readonly stickinessCookieDurationSec?: number;
+  readonly stickinessCookieDuration?: Duration;
 
   /**
    * The targets to add to this target group.
@@ -86,11 +86,11 @@ export class ApplicationTargetGroup extends TargetGroupBase implements IApplicat
     this.connectableMembers = [];
     this.listeners = [];
 
-    if (props.slowStartSec !== undefined) {
-      this.setAttribute('slow_start.duration_seconds', props.slowStartSec.toString());
+    if (props.slowStart !== undefined) {
+      this.setAttribute('slow_start.duration_seconds', props.slowStart.toSeconds().toString());
     }
-    if (props.stickinessCookieDurationSec !== undefined) {
-      this.enableCookieStickiness(props.stickinessCookieDurationSec);
+    if (props.stickinessCookieDuration !== undefined) {
+      this.enableCookieStickiness(props.stickinessCookieDuration);
     }
 
     this.addTarget(...(props.targets || []));
@@ -109,10 +109,10 @@ export class ApplicationTargetGroup extends TargetGroupBase implements IApplicat
   /**
    * Enable sticky routing via a cookie to members of this target group
    */
-  public enableCookieStickiness(durationSec: number) {
+  public enableCookieStickiness(duration: Duration) {
     this.setAttribute('stickiness.enabled', 'true');
     this.setAttribute('stickiness.type', 'lb_cookie');
-    this.setAttribute('stickiness.lb_cookie.duration_seconds', durationSec.toString());
+    this.setAttribute('stickiness.lb_cookie.duration_seconds', duration.toSeconds().toString());
   }
 
   /**
diff --git a/packages/@aws-cdk/aws-elasticloadbalancingv2/lib/nlb/network-listener.ts b/packages/@aws-cdk/aws-elasticloadbalancingv2/lib/nlb/network-listener.ts
index b84c92ca8deaa..112616f85a8d3 100644
--- a/packages/@aws-cdk/aws-elasticloadbalancingv2/lib/nlb/network-listener.ts
+++ b/packages/@aws-cdk/aws-elasticloadbalancingv2/lib/nlb/network-listener.ts
@@ -1,4 +1,4 @@
-import { Construct, IResource, Resource } from '@aws-cdk/cdk';
+import { Construct, Duration, IResource, Resource } from '@aws-cdk/cdk';
 import { BaseListener } from '../shared/base-listener';
 import { HealthCheck } from '../shared/base-target-group';
 import { Protocol, SslPolicy } from '../shared/enums';
@@ -140,7 +140,7 @@ export class NetworkListener extends BaseListener implements INetworkListener {
     }
 
     const group = new NetworkTargetGroup(this, id + 'Group', {
-      deregistrationDelaySec: props.deregistrationDelaySec,
+      deregistrationDelay: props.deregistrationDelay,
       healthCheck: props.healthCheck,
       port: props.port,
       proxyProtocolV2: props.proxyProtocolV2,
@@ -202,9 +202,9 @@ export interface AddNetworkTargetsProps {
    *
    * The range is 0-3600 seconds.
    *
-   * @default 300
+   * @default Duration.minutes(5)
    */
-  readonly deregistrationDelaySec?: number;
+  readonly deregistrationDelay?: Duration;
 
   /**
    * Indicates whether Proxy Protocol version 2 is enabled.
diff --git a/packages/@aws-cdk/aws-elasticloadbalancingv2/lib/shared/base-target-group.ts b/packages/@aws-cdk/aws-elasticloadbalancingv2/lib/shared/base-target-group.ts
index 930487f9bae5c..7b4cb5925ecea 100644
--- a/packages/@aws-cdk/aws-elasticloadbalancingv2/lib/shared/base-target-group.ts
+++ b/packages/@aws-cdk/aws-elasticloadbalancingv2/lib/shared/base-target-group.ts
@@ -31,7 +31,7 @@ export interface BaseTargetGroupProps {
    *
    * @default 300
    */
-  readonly deregistrationDelaySec?: number;
+  readonly deregistrationDelay?: cdk.Duration;
 
   /**
    * Health check configuration
@@ -59,9 +59,9 @@ export interface HealthCheck {
   /**
    * The approximate number of seconds between health checks for an individual target.
    *
-   * @default 30
+   * @default Duration.seconds(30)
    */
-  readonly intervalSecs?: number;
+  readonly interval?: cdk.Duration;
 
   /**
    * The ping path destination where Elastic Load Balancing sends health check requests.
@@ -90,13 +90,13 @@ export interface HealthCheck {
   /**
    * The amount of time, in seconds, during which no response from a target means a failed health check.
    *
-   * For Application Load Balancers, the range is 2–60 seconds and the
+   * For Application Load Balancers, the range is 2-60 seconds and the
    * default is 5 seconds. For Network Load Balancers, this is 10 seconds for
    * TCP and HTTPS health checks and 6 seconds for HTTP health checks.
    *
-   * @default 5 for ALBs, 10 or 6 for NLBs
+   * @default Duration.seconds(5) for ALBs, Duration.seconds(10) or Duration.seconds(6) for NLBs
    */
-  readonly timeoutSeconds?: number;
+  readonly timeout?: cdk.Duration;
 
   /**
    * The number of consecutive health checks successes required before considering an unhealthy target healthy.
@@ -204,8 +204,8 @@ export abstract class TargetGroupBase extends cdk.Construct implements ITargetGr
   constructor(scope: cdk.Construct, id: string, baseProps: BaseTargetGroupProps, additionalProps: any) {
     super(scope, id);
 
-    if (baseProps.deregistrationDelaySec !== undefined) {
-      this.setAttribute('deregistration_delay.timeout_seconds', baseProps.deregistrationDelaySec.toString());
+    if (baseProps.deregistrationDelay !== undefined) {
+      this.setAttribute('deregistration_delay.timeout_seconds', baseProps.deregistrationDelay.toString());
     }
 
     this.healthCheck = baseProps.healthCheck || {};
@@ -219,11 +219,15 @@ export abstract class TargetGroupBase extends cdk.Construct implements ITargetGr
       vpcId: baseProps.vpc.vpcId,
 
       // HEALTH CHECK
-      healthCheckIntervalSeconds: cdk.Lazy.numberValue({ produce: () => this.healthCheck && this.healthCheck.intervalSecs }),
+      healthCheckIntervalSeconds: cdk.Lazy.numberValue({
+        produce: () => this.healthCheck && this.healthCheck.interval && this.healthCheck.interval.toSeconds()
+      }),
       healthCheckPath: cdk.Lazy.stringValue({ produce: () => this.healthCheck && this.healthCheck.path }),
       healthCheckPort: cdk.Lazy.stringValue({ produce: () => this.healthCheck && this.healthCheck.port }),
       healthCheckProtocol: cdk.Lazy.stringValue({ produce: () => this.healthCheck && this.healthCheck.protocol }),
-      healthCheckTimeoutSeconds: cdk.Lazy.numberValue({ produce: () => this.healthCheck && this.healthCheck.timeoutSeconds }),
+      healthCheckTimeoutSeconds: cdk.Lazy.numberValue({
+        produce: () => this.healthCheck && this.healthCheck.timeout && this.healthCheck.timeout.toSeconds()
+      }),
       healthyThresholdCount: cdk.Lazy.numberValue({ produce: () => this.healthCheck && this.healthCheck.healthyThresholdCount }),
       unhealthyThresholdCount: cdk.Lazy.numberValue({ produce: () => this.healthCheck && this.healthCheck.unhealthyThresholdCount }),
       matcher: cdk.Lazy.anyValue({ produce: () => this.healthCheck && this.healthCheck.healthyHttpCodes !== undefined ? {
diff --git a/packages/@aws-cdk/aws-elasticloadbalancingv2/test/alb/test.listener.ts b/packages/@aws-cdk/aws-elasticloadbalancingv2/test/alb/test.listener.ts
index 5e77a74014285..86a5bda1fe5c3 100644
--- a/packages/@aws-cdk/aws-elasticloadbalancingv2/test/alb/test.listener.ts
+++ b/packages/@aws-cdk/aws-elasticloadbalancingv2/test/alb/test.listener.ts
@@ -292,7 +292,7 @@ export = {
       port: 80,
       targets: [new FakeSelfRegisteringTarget(stack, 'Target', vpc)]
     });
-    group.enableCookieStickiness(3600);
+    group.enableCookieStickiness(cdk.Duration.hours(1));
 
     // THEN
     expect(stack).to(haveResource('AWS::ElasticLoadBalancingV2::TargetGroup', {
@@ -329,8 +329,8 @@ export = {
     });
     group.configureHealthCheck({
       unhealthyThresholdCount: 3,
-      timeoutSeconds: 3600,
-      intervalSecs: 30,
+      timeout: cdk.Duration.hours(1),
+      interval: cdk.Duration.seconds(30),
       path: '/test',
     });
 
diff --git a/packages/@aws-cdk/aws-elasticloadbalancingv2/test/alb/test.load-balancer.ts b/packages/@aws-cdk/aws-elasticloadbalancingv2/test/alb/test.load-balancer.ts
index 0b607002a2562..9d8310e584b3d 100644
--- a/packages/@aws-cdk/aws-elasticloadbalancingv2/test/alb/test.load-balancer.ts
+++ b/packages/@aws-cdk/aws-elasticloadbalancingv2/test/alb/test.load-balancer.ts
@@ -87,7 +87,7 @@ export = {
       vpc,
       deletionProtection: true,
       http2Enabled: false,
-      idleTimeoutSecs: 1000,
+      idleTimeout: cdk.Duration.seconds(1000),
     });
 
     // THEN
diff --git a/packages/@aws-cdk/aws-elasticloadbalancingv2/test/nlb/test.listener.ts b/packages/@aws-cdk/aws-elasticloadbalancingv2/test/nlb/test.listener.ts
index 854b06801f6dc..744ccbd62c910 100644
--- a/packages/@aws-cdk/aws-elasticloadbalancingv2/test/nlb/test.listener.ts
+++ b/packages/@aws-cdk/aws-elasticloadbalancingv2/test/nlb/test.listener.ts
@@ -99,8 +99,8 @@ export = {
       targets: [new FakeSelfRegisteringTarget(stack, 'Target', vpc)]
     });
     group.configureHealthCheck({
-      timeoutSeconds: 3600,
-      intervalSecs: 30,
+      timeout: cdk.Duration.hours(1),
+      interval: cdk.Duration.seconds(30),
       path: '/test',
     });
 
diff --git a/packages/@aws-cdk/aws-events-targets/test/stepfunctions/statemachine.test.ts b/packages/@aws-cdk/aws-events-targets/test/stepfunctions/statemachine.test.ts
index 5e29cd47b046c..840f9ae418162 100644
--- a/packages/@aws-cdk/aws-events-targets/test/stepfunctions/statemachine.test.ts
+++ b/packages/@aws-cdk/aws-events-targets/test/stepfunctions/statemachine.test.ts
@@ -11,7 +11,7 @@ test('State machine can be used as Event Rule target', () => {
     scheduleExpression: 'rate(1 minute)'
   });
   const stateMachine = new sfn.StateMachine(stack, 'SM', {
-    definition: new sfn.Wait(stack, 'Hello', { duration: sfn.WaitDuration.seconds(10) })
+    definition: new sfn.Wait(stack, 'Hello', { time: sfn.WaitTime.duration(cdk.Duration.seconds(10)) })
   });
 
   // WHEN
diff --git a/packages/@aws-cdk/aws-iam/lib/role.ts b/packages/@aws-cdk/aws-iam/lib/role.ts
index 3f59ae06fcc77..53b19ac53fd8a 100644
--- a/packages/@aws-cdk/aws-iam/lib/role.ts
+++ b/packages/@aws-cdk/aws-iam/lib/role.ts
@@ -1,4 +1,4 @@
-import { Construct, PhysicalName, Resource, ResourceIdentifiers, Stack } from '@aws-cdk/cdk';
+import { Construct, Duration, PhysicalName, Resource, ResourceIdentifiers, Stack, toSeconds } from '@aws-cdk/cdk';
 import { Grant } from './grant';
 import { CfnRole } from './iam.generated';
 import { IIdentity } from './identity-base';
@@ -71,9 +71,8 @@ export interface RoleProps {
   readonly roleName?: PhysicalName;
 
   /**
-   * The maximum session duration (in seconds) that you want to set for the
-   * specified role. This setting can have a value from 1 hour (3600sec) to
-   * 12 (43200sec) hours.
+   * The maximum session duration that you want to set for the specified role.
+   * This setting can have a value from 1 hour (3600sec) to 12 (43200sec) hours.
    *
    * Anyone who assumes the role from the AWS CLI or API can use the
    * DurationSeconds API parameter or the duration-seconds CLI parameter to
@@ -88,9 +87,9 @@ export interface RoleProps {
    *
    * @link https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_use.html
    *
-   * @default 3600 (1 hour)
+   * @default Duration.hours(1)
    */
-  readonly maxSessionDurationSec?: number;
+  readonly maxSessionDuration?: Duration;
 }
 
 /**
@@ -197,7 +196,8 @@ export class Role extends Resource implements IRole {
     this.assumeRolePolicy = createAssumeRolePolicy(props.assumedBy, props.externalId);
     this.managedPolicyArns = props.managedPolicyArns || [ ];
 
-    validateMaxSessionDuration(props.maxSessionDurationSec);
+    const maxSessionDuration = toSeconds(props.maxSessionDuration);
+    validateMaxSessionDuration(maxSessionDuration);
 
     const role = new CfnRole(this, 'Resource', {
       assumeRolePolicyDocument: this.assumeRolePolicy as any,
@@ -205,7 +205,7 @@ export class Role extends Resource implements IRole {
       policies: _flatten(props.inlinePolicies),
       path: props.path,
       roleName: this.physicalName.value,
-      maxSessionDuration: props.maxSessionDurationSec,
+      maxSessionDuration,
     });
 
     this.roleId = role.roleId;
diff --git a/packages/@aws-cdk/aws-iam/test/test.role.ts b/packages/@aws-cdk/aws-iam/test/test.role.ts
index c3783e814ba4d..30618533ce9d9 100644
--- a/packages/@aws-cdk/aws-iam/test/test.role.ts
+++ b/packages/@aws-cdk/aws-iam/test/test.role.ts
@@ -1,5 +1,5 @@
 import { expect, haveResource, haveResourceLike } from '@aws-cdk/assert';
-import { Stack } from '@aws-cdk/cdk';
+import { Duration, Stack } from '@aws-cdk/cdk';
 import { Test } from 'nodeunit';
 import { ArnPrincipal, CompositePrincipal, FederatedPrincipal, PolicyStatement, Role, ServicePrincipal, User } from '../lib';
 
@@ -194,7 +194,7 @@ export = {
     'can be used to specify the maximum session duration for assuming the role'(test: Test) {
       const stack = new Stack();
 
-      new Role(stack, 'MyRole', { maxSessionDurationSec: 3700, assumedBy: new ServicePrincipal('sns.amazonaws.com') });
+      new Role(stack, 'MyRole', { maxSessionDuration: Duration.seconds(3700), assumedBy: new ServicePrincipal('sns.amazonaws.com') });
 
       expect(stack).to(haveResource('AWS::IAM::Role', {
         MaxSessionDuration: 3700
@@ -208,13 +208,13 @@ export = {
 
       const assumedBy = new ServicePrincipal('bla');
 
-      new Role(stack, 'MyRole1', { assumedBy, maxSessionDurationSec: 3600 });
-      new Role(stack, 'MyRole2', { assumedBy, maxSessionDurationSec: 43200 });
+      new Role(stack, 'MyRole1', { assumedBy, maxSessionDuration: Duration.hours(1) });
+      new Role(stack, 'MyRole2', { assumedBy, maxSessionDuration: Duration.hours(12) });
 
       const expected = (val: any) => `maxSessionDuration is set to ${val}, but must be >= 3600sec (1hr) and <= 43200sec (12hrs)`;
-      test.throws(() => new Role(stack, 'MyRole3', { assumedBy, maxSessionDurationSec: 60 }), expected(60));
-      test.throws(() => new Role(stack, 'MyRole4', { assumedBy, maxSessionDurationSec: 3599 }), expected(3599));
-      test.throws(() => new Role(stack, 'MyRole5', { assumedBy, maxSessionDurationSec: 43201 }), expected(43201));
+      test.throws(() => new Role(stack, 'MyRole3', { assumedBy, maxSessionDuration: Duration.minutes(1) }), expected(60));
+      test.throws(() => new Role(stack, 'MyRole4', { assumedBy, maxSessionDuration: Duration.seconds(3599) }), expected(3599));
+      test.throws(() => new Role(stack, 'MyRole5', { assumedBy, maxSessionDuration: Duration.seconds(43201) }), expected(43201));
 
       test.done();
     }
diff --git a/packages/@aws-cdk/aws-lambda/lib/function.ts b/packages/@aws-cdk/aws-lambda/lib/function.ts
index 5151cf57eb958..b66e4a1920adb 100644
--- a/packages/@aws-cdk/aws-lambda/lib/function.ts
+++ b/packages/@aws-cdk/aws-lambda/lib/function.ts
@@ -3,7 +3,7 @@ import ec2 = require('@aws-cdk/aws-ec2');
 import iam = require('@aws-cdk/aws-iam');
 import logs = require('@aws-cdk/aws-logs');
 import sqs = require('@aws-cdk/aws-sqs');
-import { Construct, Fn, Lazy, Stack } from '@aws-cdk/cdk';
+import { Construct, Duration, Fn, Lazy, Stack, toSeconds } from '@aws-cdk/cdk';
 import { Code } from './code';
 import { IEventSource } from './event-source';
 import { FunctionAttributes, FunctionBase, IFunction } from './function-base';
@@ -64,9 +64,9 @@ export interface FunctionProps {
    * the function. Because the execution time affects cost, set this value
    * based on the function's expected execution time.
    *
-   * @default 3
+   * @default Duration.seconds(3)
    */
-  readonly timeout?: number;
+  readonly timeout?: Duration;
 
   /**
    * Key-value pairs that Lambda caches and makes available for your Lambda
@@ -219,7 +219,7 @@ export interface FunctionProps {
    *
    * @default - Logs never expire.
    */
-  readonly logRetentionDays?: logs.RetentionDays;
+  readonly logRetention?: logs.RetentionDays;
 }
 
 /**
@@ -427,7 +427,7 @@ export class Function extends FunctionBase {
       code: Lazy.anyValue({ produce: () => props.code._toJSON(resource) }),
       layers: Lazy.listValue({ produce: () => this.layers.map(layer => layer.layerVersionArn) }, { omitEmpty: true }),
       handler: props.handler,
-      timeout: props.timeout,
+      timeout: toSeconds(props.timeout),
       runtime: props.runtime.name,
       role: this.role.roleArn,
       environment: Lazy.anyValue({ produce: () => this.renderEnvironment() }),
@@ -457,10 +457,10 @@ export class Function extends FunctionBase {
     }
 
     // Log retention
-    if (props.logRetentionDays) {
+    if (props.logRetention) {
       new LogRetention(this, 'LogRetention', {
         logGroupName: `/aws/lambda/${this.functionName}`,
-        retentionDays: props.logRetentionDays
+        retention: props.logRetention
       });
     }
   }
@@ -609,7 +609,7 @@ export class Function extends FunctionBase {
     }
 
     const deadLetterQueue = props.deadLetterQueue || new sqs.Queue(this, 'DeadLetterQueue', {
-      retentionPeriodSec: 1209600
+      retentionPeriod: Duration.days(14)
     });
 
     this.addToRolePolicy(new iam.PolicyStatement()
diff --git a/packages/@aws-cdk/aws-lambda/lib/log-retention.ts b/packages/@aws-cdk/aws-lambda/lib/log-retention.ts
index 1196f04d38012..95dd25ff16cce 100644
--- a/packages/@aws-cdk/aws-lambda/lib/log-retention.ts
+++ b/packages/@aws-cdk/aws-lambda/lib/log-retention.ts
@@ -18,7 +18,7 @@ export interface LogRetentionProps {
   /**
    * The number of days log events are kept in CloudWatch Logs.
    */
-  readonly retentionDays: logs.RetentionDays;
+  readonly retention: logs.RetentionDays;
 }
 
 /**
@@ -55,7 +55,7 @@ export class LogRetention extends cdk.Construct {
       properties: {
         ServiceToken: provider.functionArn,
         LogGroupName: props.logGroupName,
-        RetentionInDays: props.retentionDays === Infinity ? undefined : props.retentionDays
+        RetentionInDays: props.retention === Infinity ? undefined : props.retention
       }
     });
   }
diff --git a/packages/@aws-cdk/aws-lambda/test/integ.log-retention.ts b/packages/@aws-cdk/aws-lambda/test/integ.log-retention.ts
index cc52b278fb857..1be7666cded7e 100644
--- a/packages/@aws-cdk/aws-lambda/test/integ.log-retention.ts
+++ b/packages/@aws-cdk/aws-lambda/test/integ.log-retention.ts
@@ -10,21 +10,21 @@ new lambda.Function(stack, 'OneWeek', {
   code: new lambda.InlineCode('exports.handler = (event) => console.log(JSON.stringify(event));'),
   handler: 'index.handler',
   runtime: lambda.Runtime.NodeJS810,
-  logRetentionDays: logs.RetentionDays.OneWeek
+  logRetention: logs.RetentionDays.OneWeek
 });
 
 new lambda.Function(stack, 'OneMonth', {
   code: new lambda.InlineCode('exports.handler = (event) => console.log(JSON.stringify(event));'),
   handler: 'index.handler',
   runtime: lambda.Runtime.NodeJS810,
-  logRetentionDays: logs.RetentionDays.OneMonth
+  logRetention: logs.RetentionDays.OneMonth
 });
 
 new lambda.Function(stack, 'OneYear', {
   code: new lambda.InlineCode('exports.handler = (event) => console.log(JSON.stringify(event));'),
   handler: 'index.handler',
   runtime: lambda.Runtime.NodeJS810,
-  logRetentionDays: logs.RetentionDays.OneYear
+  logRetention: logs.RetentionDays.OneYear
 });
 
 app.synth();
diff --git a/packages/@aws-cdk/aws-lambda/test/test.lambda.ts b/packages/@aws-cdk/aws-lambda/test/test.lambda.ts
index f491ff4eb101c..918b5f6fafff7 100644
--- a/packages/@aws-cdk/aws-lambda/test/test.lambda.ts
+++ b/packages/@aws-cdk/aws-lambda/test/test.lambda.ts
@@ -583,7 +583,7 @@ export = {
 
     const dlQueue = new sqs.Queue(stack, 'DeadLetterQueue', {
       queueName: 'MyLambda_DLQ',
-      retentionPeriodSec: 1209600
+      retentionPeriod: cdk.Duration.days(14)
     });
 
     new lambda.Function(stack, 'MyLambda', {
@@ -692,7 +692,7 @@ export = {
 
     const dlQueue = new sqs.Queue(stack, 'DeadLetterQueue', {
       queueName: 'MyLambda_DLQ',
-      retentionPeriodSec: 1209600
+      retentionPeriod: cdk.Duration.days(14)
     });
 
     new lambda.Function(stack, 'MyLambda', {
@@ -802,7 +802,7 @@ export = {
 
     const dlQueue = new sqs.Queue(stack, 'DeadLetterQueue', {
       queueName: 'MyLambda_DLQ',
-      retentionPeriodSec: 1209600
+      retentionPeriod: cdk.Duration.days(14)
     });
 
     test.throws(() => new lambda.Function(stack, 'MyLambda', {
@@ -1088,7 +1088,7 @@ export = {
       dimensions: { FunctionName: { Ref: 'Function76856677' }},
       namespace: 'AWS/Lambda',
       metricName: 'Errors',
-      periodSec: 300,
+      period: cdk.Duration.minutes(5),
       statistic: 'Sum',
     });
 
@@ -1323,7 +1323,7 @@ export = {
       code: new lambda.InlineCode('foo'),
       handler: 'index.handler',
       runtime: lambda.Runtime.NodeJS,
-      logRetentionDays: logs.RetentionDays.OneMonth
+      logRetention: logs.RetentionDays.OneMonth
     });
 
     // THEN
diff --git a/packages/@aws-cdk/aws-lambda/test/test.log-retention.ts b/packages/@aws-cdk/aws-lambda/test/test.log-retention.ts
index be223b42148d7..c5409df0527f5 100644
--- a/packages/@aws-cdk/aws-lambda/test/test.log-retention.ts
+++ b/packages/@aws-cdk/aws-lambda/test/test.log-retention.ts
@@ -14,7 +14,7 @@ export = {
     // WHEN
     new lambda.LogRetention(stack, 'MyLambda', {
       logGroupName: 'group',
-      retentionDays: logs.RetentionDays.OneMonth
+      retention: logs.RetentionDays.OneMonth
     });
 
     // THEN
diff --git a/packages/@aws-cdk/aws-lambda/test/test.singleton-lambda.ts b/packages/@aws-cdk/aws-lambda/test/test.singleton-lambda.ts
index 5a49886d7658b..74b02f61e6890 100644
--- a/packages/@aws-cdk/aws-lambda/test/test.singleton-lambda.ts
+++ b/packages/@aws-cdk/aws-lambda/test/test.singleton-lambda.ts
@@ -15,7 +15,7 @@ export = {
     code: new lambda.InlineCode('def hello(): pass'),
     runtime: lambda.Runtime.Python27,
     handler: 'index.hello',
-    timeout: 300,
+    timeout: cdk.Duration.minutes(5),
     });
   }
 
diff --git a/packages/@aws-cdk/aws-logs/lib/log-group.ts b/packages/@aws-cdk/aws-logs/lib/log-group.ts
index 6881d573ecc0f..834487e094cb6 100644
--- a/packages/@aws-cdk/aws-logs/lib/log-group.ts
+++ b/packages/@aws-cdk/aws-logs/lib/log-group.ts
@@ -284,9 +284,9 @@ export interface LogGroupProps {
    *
    * To retain all logs, set this value to Infinity.
    *
-   * @default 731 days (2 years)
+   * @default RetentionDays.TwoYears
    */
-  readonly retentionDays?: RetentionDays;
+  readonly retention?: RetentionDays;
 
   /**
    * Retain the log group if the stack or containing construct ceases to exist
@@ -330,7 +330,7 @@ export class LogGroup extends LogGroupBase {
   constructor(scope: Construct, id: string, props: LogGroupProps = {}) {
     super(scope, id);
 
-    let retentionInDays = props.retentionDays;
+    let retentionInDays = props.retention;
     if (retentionInDays === undefined) { retentionInDays = RetentionDays.TwoYears; }
     if (retentionInDays === Infinity) { retentionInDays = undefined; }
 
diff --git a/packages/@aws-cdk/aws-logs/package.json b/packages/@aws-cdk/aws-logs/package.json
index 660e812aa68bc..f1db7cef9885e 100644
--- a/packages/@aws-cdk/aws-logs/package.json
+++ b/packages/@aws-cdk/aws-logs/package.json
@@ -89,4 +89,4 @@
     ]
   },
   "stability": "experimental"
-}
\ No newline at end of file
+}
diff --git a/packages/@aws-cdk/aws-logs/test/example.retention.lit.ts b/packages/@aws-cdk/aws-logs/test/example.retention.lit.ts
index ed0fd084e18d4..4ba54c254178f 100644
--- a/packages/@aws-cdk/aws-logs/test/example.retention.lit.ts
+++ b/packages/@aws-cdk/aws-logs/test/example.retention.lit.ts
@@ -7,7 +7,7 @@ function shortLogGroup() {
   /// !show
   // Configure log group for short retention
   const logGroup = new LogGroup(stack, 'LogGroup', {
-    retentionDays: RetentionDays.OneWeek
+    retention: RetentionDays.OneWeek
   });
   /// !hide
   return logGroup;
@@ -17,7 +17,7 @@ function infiniteLogGroup() {
   /// !show
   // Configure log group for infinite retention
   const logGroup = new LogGroup(stack, 'LogGroup', {
-    retentionDays: Infinity
+    retention: Infinity
   });
   /// !hide
   return logGroup;
diff --git a/packages/@aws-cdk/aws-logs/test/test.loggroup.ts b/packages/@aws-cdk/aws-logs/test/test.loggroup.ts
index 16d13706284d0..0c08cdfd16a57 100644
--- a/packages/@aws-cdk/aws-logs/test/test.loggroup.ts
+++ b/packages/@aws-cdk/aws-logs/test/test.loggroup.ts
@@ -11,7 +11,7 @@ export = {
 
     // WHEN
     new LogGroup(stack, 'LogGroup', {
-      retentionDays: RetentionDays.OneWeek
+      retention: RetentionDays.OneWeek
     });
 
     // THEN
@@ -43,7 +43,7 @@ export = {
 
     // WHEN
     new LogGroup(stack, 'LogGroup', {
-      retentionDays: Infinity
+      retention: Infinity
     });
 
     // THEN
@@ -65,7 +65,7 @@ export = {
 
     // WHEN
     new LogGroup(stack, 'LogGroup', {
-      retentionDays: Infinity,
+      retention: Infinity,
       retainLogGroup: false
     });
 
diff --git a/packages/@aws-cdk/aws-rds/lib/cluster.ts b/packages/@aws-cdk/aws-rds/lib/cluster.ts
index 082a14efa92fc..c50ae5e43045b 100644
--- a/packages/@aws-cdk/aws-rds/lib/cluster.ts
+++ b/packages/@aws-cdk/aws-rds/lib/cluster.ts
@@ -312,7 +312,7 @@ export class DatabaseCluster extends DatabaseClusterBase {
         : (props.masterUser.password
             ? props.masterUser.password.toString()
             : undefined),
-      backupRetentionPeriod: props.backup && props.backup.retentionDays,
+      backupRetentionPeriod: props.backup && props.backup.retention && props.backup.retention.toDays(),
       preferredBackupWindow: props.backup && props.backup.preferredWindow,
       preferredMaintenanceWindow: props.preferredMaintenanceWindow,
       databaseName: props.defaultDatabaseName,
diff --git a/packages/@aws-cdk/aws-rds/lib/instance.ts b/packages/@aws-cdk/aws-rds/lib/instance.ts
index 3ae8dd578f85e..4a3c063ee0b45 100644
--- a/packages/@aws-cdk/aws-rds/lib/instance.ts
+++ b/packages/@aws-cdk/aws-rds/lib/instance.ts
@@ -5,7 +5,7 @@ import kms = require('@aws-cdk/aws-kms');
 import lambda = require('@aws-cdk/aws-lambda');
 import logs = require('@aws-cdk/aws-logs');
 import secretsmanager = require('@aws-cdk/aws-secretsmanager');
-import { Construct, DeletionPolicy, IResource, Resource, SecretValue, Stack, Token } from '@aws-cdk/cdk';
+import { Construct, DeletionPolicy, Duration, IResource, Resource, SecretValue, Stack, Token, toSeconds } from '@aws-cdk/cdk';
 import { DatabaseSecret } from './database-secret';
 import { Endpoint } from './endpoint';
 import { IOptionGroup} from './option-group';
@@ -225,7 +225,7 @@ export enum StorageType {
 /**
  * The retention period for Performance Insight.
  */
-export enum PerformanceInsightRetentionPeriod {
+export enum PerformanceInsightRetention {
   /**
    * Default retention period of 7 days.
    */
@@ -333,7 +333,7 @@ export interface DatabaseInstanceNewProps {
    *
    * @default 1 day
    */
-  readonly backupRetentionPeriod?: number;
+  readonly backupRetention?: Duration;
 
   /**
    * The daily time range during which automated backups are performed.
@@ -372,7 +372,7 @@ export interface DatabaseInstanceNewProps {
    *
    * @default no enhanced monitoring
    */
-  readonly monitoringInterval?: number;
+  readonly monitoringInterval?: Duration;
 
   /**
    * Whether to enable Performance Insights for the DB instance.
@@ -386,7 +386,7 @@ export interface DatabaseInstanceNewProps {
    *
    * @default 7 days
    */
-  readonly performanceInsightRetentionPeriod?: PerformanceInsightRetentionPeriod;
+  readonly performanceInsightRetention?: PerformanceInsightRetention;
 
   /**
    * The AWS KMS key for encryption of Performance Insights data.
@@ -507,7 +507,7 @@ abstract class DatabaseInstanceNew extends DatabaseInstanceBase implements IData
     this.newCfnProps = {
       autoMinorVersionUpgrade: props.autoMinorVersionUpgrade,
       availabilityZone: props.multiAz ? undefined : props.availabilityZone,
-      backupRetentionPeriod: props.backupRetentionPeriod ? props.backupRetentionPeriod.toString() : undefined,
+      backupRetentionPeriod: props.backupRetention ? props.backupRetention.toDays().toString() : undefined,
       copyTagsToSnapshot: props.copyTagsToSnapshot !== undefined ? props.copyTagsToSnapshot : true,
       dbInstanceClass: `db.${props.instanceClass}`,
       dbInstanceIdentifier: props.instanceIdentifier,
@@ -518,7 +518,7 @@ abstract class DatabaseInstanceNew extends DatabaseInstanceBase implements IData
       enableIamDatabaseAuthentication: props.iamAuthentication,
       enablePerformanceInsights: props.enablePerformanceInsights,
       iops,
-      monitoringInterval: props.monitoringInterval,
+      monitoringInterval: toSeconds(props.monitoringInterval),
       monitoringRoleArn: monitoringRole && monitoringRole.roleArn,
       multiAz: props.multiAz,
       optionGroupName: props.optionGroup && props.optionGroup.optionGroupName,
@@ -526,7 +526,7 @@ abstract class DatabaseInstanceNew extends DatabaseInstanceBase implements IData
         ? props.performanceInsightKmsKey && props.performanceInsightKmsKey.keyArn
         : undefined,
       performanceInsightsRetentionPeriod: props.enablePerformanceInsights
-        ? (props.performanceInsightRetentionPeriod || PerformanceInsightRetentionPeriod.Default)
+        ? (props.performanceInsightRetention || PerformanceInsightRetention.Default)
         : undefined,
       port: props.port ? props.port.toString() : undefined,
       preferredBackupWindow: props.preferredBackupWindow,
@@ -543,7 +543,7 @@ abstract class DatabaseInstanceNew extends DatabaseInstanceBase implements IData
       for (const log of this.cloudwatchLogsExports) {
         new lambda.LogRetention(this, `LogRetention${log}`, {
           logGroupName: `/aws/rds/instance/${this.instanceIdentifier}/${log}`,
-          retentionDays: this.cloudwatchLogsRetention
+          retention: this.cloudwatchLogsRetention
         });
       }
     }
diff --git a/packages/@aws-cdk/aws-rds/lib/props.ts b/packages/@aws-cdk/aws-rds/lib/props.ts
index cde179018c92d..ff26825559cb2 100644
--- a/packages/@aws-cdk/aws-rds/lib/props.ts
+++ b/packages/@aws-cdk/aws-rds/lib/props.ts
@@ -1,6 +1,6 @@
 import ec2 = require('@aws-cdk/aws-ec2');
 import kms = require('@aws-cdk/aws-kms');
-import { SecretValue } from '@aws-cdk/cdk';
+import { Duration, SecretValue } from '@aws-cdk/cdk';
 import { IParameterGroup } from './parameter-group';
 import { SecretRotationApplication } from './secret-rotation';
 
@@ -80,7 +80,7 @@ export interface BackupProps {
   /**
    * How many days to retain the backup
    */
-  readonly retentionDays: number;
+  readonly retention: Duration;
 
   /**
    * A daily time range in 24-hours UTC format in which backups preferably execute.
diff --git a/packages/@aws-cdk/aws-rds/lib/secret-rotation.ts b/packages/@aws-cdk/aws-rds/lib/secret-rotation.ts
index b17ce3903cbb6..5bf663f6002f0 100644
--- a/packages/@aws-cdk/aws-rds/lib/secret-rotation.ts
+++ b/packages/@aws-cdk/aws-rds/lib/secret-rotation.ts
@@ -2,7 +2,7 @@ import ec2 = require('@aws-cdk/aws-ec2');
 import lambda = require('@aws-cdk/aws-lambda');
 import serverless = require('@aws-cdk/aws-sam');
 import secretsmanager = require('@aws-cdk/aws-secretsmanager');
-import { Construct, Stack } from '@aws-cdk/cdk';
+import { Construct, Duration, Stack } from '@aws-cdk/cdk';
 
 /**
  * A secret rotation serverless application.
@@ -40,9 +40,9 @@ export interface SecretRotationOptions {
    * Specifies the number of days after the previous rotation before
    * Secrets Manager triggers the next automatic rotation.
    *
-   * @default 30 days
+   * @default Duration.days(30)
    */
-  readonly automaticallyAfterDays?: number;
+  readonly automaticallyAfter?: Duration;
 }
 
 /**
@@ -139,7 +139,7 @@ export class SecretRotation extends Construct {
 
     const rotationSchedule = props.secret.addRotationSchedule('RotationSchedule', {
       rotationLambda,
-      automaticallyAfterDays: props.automaticallyAfterDays
+      automaticallyAfter: props.automaticallyAfter
     });
     rotationSchedule.node.addDependency(permission); // Cannot rotate without permission
   }
diff --git a/packages/@aws-cdk/aws-rds/test/integ.instance.lit.ts b/packages/@aws-cdk/aws-rds/test/integ.instance.lit.ts
index 5229eb8cf3b41..92a78aa5edc14 100644
--- a/packages/@aws-cdk/aws-rds/test/integ.instance.lit.ts
+++ b/packages/@aws-cdk/aws-rds/test/integ.instance.lit.ts
@@ -53,8 +53,8 @@ class DatabaseInstanceStack extends cdk.Stack {
       vpc,
       databaseName: 'ORCL',
       storageEncrypted: true,
-      backupRetentionPeriod: 7,
-      monitoringInterval: 60,
+      backupRetention: cdk.Duration.days(7),
+      monitoringInterval: cdk.Duration.seconds(60),
       enablePerformanceInsights: true,
       cloudwatchLogsExports: [
         'trace',
diff --git a/packages/@aws-cdk/aws-rds/test/test.instance.ts b/packages/@aws-cdk/aws-rds/test/test.instance.ts
index 441fa691e6151..a65a8b1c601a6 100644
--- a/packages/@aws-cdk/aws-rds/test/test.instance.ts
+++ b/packages/@aws-cdk/aws-rds/test/test.instance.ts
@@ -24,8 +24,8 @@ export = {
       vpc,
       databaseName: 'ORCL',
       storageEncrypted: true,
-      backupRetentionPeriod: 7,
-      monitoringInterval: 60,
+      backupRetention: cdk.Duration.days(7),
+      monitoringInterval: cdk.Duration.seconds(60),
       enablePerformanceInsights: true,
       cloudwatchLogsExports: [
         'trace',
@@ -39,74 +39,70 @@ export = {
 
     // THEN
     expect(stack).to(haveResource('AWS::RDS::DBInstance', {
-      Properties: {
-        DBInstanceClass: 'db.t2.medium',
-        AllocatedStorage: '100',
-        AutoMinorVersionUpgrade: false,
-        BackupRetentionPeriod: '7',
-        CopyTagsToSnapshot: true,
-        DBName: 'ORCL',
-        DBSubnetGroupName: {
-          Ref: 'InstanceSubnetGroupF2CBA54F'
-        },
-        DeletionProtection: true,
-        EnableCloudwatchLogsExports: [
-          'trace',
-          'audit',
-          'alert',
-          'listener'
-        ],
-        EnablePerformanceInsights: true,
-        Engine: 'oracle-se1',
-        Iops: 1000,
-        LicenseModel: 'bring-your-own-license',
-        MasterUsername: {
-          'Fn::Join': [
-            '',
-            [
-              '{{resolve:secretsmanager:',
-              {
-                Ref: 'InstanceSecret478E0A47'
-              },
-              ':SecretString:username::}}'
-            ]
-          ]
-        },
-        MasterUserPassword: {
-          'Fn::Join': [
-            '',
-            [
-              '{{resolve:secretsmanager:',
-              {
-                Ref: 'InstanceSecret478E0A47'
-              },
-              ':SecretString:password::}}'
-            ]
+      DBInstanceClass: 'db.t2.medium',
+      AllocatedStorage: '100',
+      AutoMinorVersionUpgrade: false,
+      BackupRetentionPeriod: '7',
+      CopyTagsToSnapshot: true,
+      DBName: 'ORCL',
+      DBSubnetGroupName: {
+        Ref: 'InstanceSubnetGroupF2CBA54F'
+      },
+      DeletionProtection: true,
+      EnableCloudwatchLogsExports: [
+        'trace',
+        'audit',
+        'alert',
+        'listener'
+      ],
+      EnablePerformanceInsights: true,
+      Engine: 'oracle-se1',
+      Iops: 1000,
+      LicenseModel: 'bring-your-own-license',
+      MasterUsername: {
+        'Fn::Join': [
+          '',
+          [
+            '{{resolve:secretsmanager:',
+            {
+              Ref: 'InstanceSecret478E0A47'
+            },
+            ':SecretString:username::}}'
           ]
-        },
-        MonitoringInterval: 60,
-        MonitoringRoleArn: {
-          'Fn::GetAtt': [
-            'InstanceMonitoringRole3E2B4286',
-            'Arn'
+        ]
+      },
+      MasterUserPassword: {
+        'Fn::Join': [
+          '',
+          [
+            '{{resolve:secretsmanager:',
+            {
+              Ref: 'InstanceSecret478E0A47'
+            },
+            ':SecretString:password::}}'
           ]
-        },
-        MultiAZ: true,
-        PerformanceInsightsRetentionPeriod: 7,
-        StorageEncrypted: true,
-        StorageType: 'io1',
-        VPCSecurityGroups: [
-          {
-            'Fn::GetAtt': [
-              'InstanceSecurityGroupB4E5FA83',
-              'GroupId'
-            ]
-          }
         ]
       },
-      DeletionPolicy: 'Retain',
-      UpdateReplacePolicy: 'Retain'
-    }, ResourcePart.CompleteDefinition));
+      MonitoringInterval: 60,
+      MonitoringRoleArn: {
+        'Fn::GetAtt': [
+          'InstanceMonitoringRole3E2B4286',
+          'Arn'
+        ]
+      },
+      MultiAZ: true,
+      PerformanceInsightsRetentionPeriod: 7,
+      StorageEncrypted: true,
+      StorageType: 'io1',
+      VPCSecurityGroups: [
+        {
+          'Fn::GetAtt': [
+            'InstanceSecurityGroupB4E5FA83',
+            'GroupId'
+          ]
+        }
+      ]
+    }));
 
     expect(stack).to(haveResource('AWS::RDS::DBInstance', {
       DeletionPolicy: 'Retain',
@@ -371,7 +367,7 @@ export = {
       dimensions: { DBInstanceIdentifier: { Ref: 'InstanceC1063A87' } },
       namespace: 'AWS/RDS',
       metricName: 'CPUUtilization',
-      periodSec: 300,
+      period: cdk.Duration.minutes(5),
       statistic: 'Average'
     });
 
diff --git a/packages/@aws-cdk/aws-route53/lib/hosted-zone.ts b/packages/@aws-cdk/aws-route53/lib/hosted-zone.ts
index fe3bf4b13a34e..bdb4099605ae6 100644
--- a/packages/@aws-cdk/aws-route53/lib/hosted-zone.ts
+++ b/packages/@aws-cdk/aws-route53/lib/hosted-zone.ts
@@ -1,5 +1,5 @@
 import ec2 = require('@aws-cdk/aws-ec2');
-import { Construct, Lazy, Resource } from '@aws-cdk/cdk';
+import { Construct, Duration, Lazy, Resource } from '@aws-cdk/cdk';
 import { HostedZoneAttributes, IHostedZone } from './hosted-zone-ref';
 import { CaaAmazonRecord, ZoneDelegationRecord } from './record-set';
 import { CfnHostedZone } from './route53.generated';
@@ -184,7 +184,7 @@ export interface ZoneDelegationOptions {
    *
    * @default 172800
    */
-  readonly ttl?: number;
+  readonly ttl?: Duration;
 }
 
 export interface PrivateHostedZoneProps extends CommonHostedZoneProps {
diff --git a/packages/@aws-cdk/aws-route53/lib/record-set.ts b/packages/@aws-cdk/aws-route53/lib/record-set.ts
index 1d178c6abc69d..8bc4a272233a1 100644
--- a/packages/@aws-cdk/aws-route53/lib/record-set.ts
+++ b/packages/@aws-cdk/aws-route53/lib/record-set.ts
@@ -1,4 +1,4 @@
-import { Construct, IResource, Resource, Token } from '@aws-cdk/cdk';
+import { Construct, Duration, IResource, Resource, Token, toSeconds } from '@aws-cdk/cdk';
 import { IAliasRecordTarget } from './alias-record-target';
 import { IHostedZone } from './hosted-zone-ref';
 import { CfnRecordSet } from './route53.generated';
@@ -49,11 +49,11 @@ export interface RecordSetOptions {
   readonly recordName?: string;
 
   /**
-   * The resource record cache time to live (TTL) in seconds.
+   * The resource record cache time to live (TTL).
    *
-   * @default 1800 seconds
+   * @default Duration.minutes(30)
    */
-  readonly ttl?: number;
+  readonly ttl?: Duration;
 
   /**
    * A comment to add on the record.
@@ -110,7 +110,7 @@ export class RecordSet extends Resource implements IRecordSet {
   constructor(scope: Construct, id: string, props: RecordSetProps) {
     super(scope, id);
 
-    const ttl = props.target.aliasTarget ? undefined : (props.ttl || 1800).toString();
+    const ttl = props.target.aliasTarget ? undefined : (toSeconds(props.ttl) || 1800).toString();
 
     const recordSet = new CfnRecordSet(this, 'Resource', {
       hostedZoneId: props.zone.hostedZoneId,
@@ -446,7 +446,7 @@ export class ZoneDelegationRecord extends RecordSet {
         ? props.nameServers // Can't map a string-array token!
         : props.nameServers.map(ns => (Token.isUnresolved(ns) || ns.endsWith('.')) ? ns : `${ns}.`)
       ),
-      ttl: props.ttl || 172_800
+      ttl: props.ttl || Duration.days(2)
     });
   }
 }
diff --git a/packages/@aws-cdk/aws-route53/test/integ.route53.ts b/packages/@aws-cdk/aws-route53/test/integ.route53.ts
index 544c84e09b80c..f50521f546257 100644
--- a/packages/@aws-cdk/aws-route53/test/integ.route53.ts
+++ b/packages/@aws-cdk/aws-route53/test/integ.route53.ts
@@ -27,7 +27,7 @@ new TxtRecord(privateZone, 'TXT', {
     'Bar!',
     'Baz?'
   ],
-  ttl: 60
+  ttl: cdk.Duration.minutes(1)
 });
 
 new CnameRecord(stack, 'CNAME', {
diff --git a/packages/@aws-cdk/aws-route53/test/test.record-set.ts b/packages/@aws-cdk/aws-route53/test/test.record-set.ts
index 8dca376245ab5..e455961379c72 100644
--- a/packages/@aws-cdk/aws-route53/test/test.record-set.ts
+++ b/packages/@aws-cdk/aws-route53/test/test.record-set.ts
@@ -1,5 +1,5 @@
 import { expect, haveResource } from '@aws-cdk/assert';
-import { Stack } from '@aws-cdk/cdk';
+import { Duration, Stack } from '@aws-cdk/cdk';
 import { Test } from 'nodeunit';
 import route53 = require('../lib');
 
@@ -49,7 +49,7 @@ export = {
       recordName: 'aa',
       recordType: route53.RecordType.CNAME,
       target: route53.RecordTarget.fromValues('bbb'),
-      ttl: 6077
+      ttl: Duration.seconds(6077)
     });
 
     // THEN
diff --git a/packages/@aws-cdk/aws-route53/test/test.route53.ts b/packages/@aws-cdk/aws-route53/test/test.route53.ts
index e5cac2f6a1879..1eb06a4e82556 100644
--- a/packages/@aws-cdk/aws-route53/test/test.route53.ts
+++ b/packages/@aws-cdk/aws-route53/test/test.route53.ts
@@ -182,7 +182,7 @@ export = {
     const delegate = new PublicHostedZone(stack, 'SubZone', { zoneName: 'sub.top.test' });
 
     // WHEN
-    zone.addDelegation(delegate, { ttl: 1337 });
+    zone.addDelegation(delegate, { ttl: cdk.Duration.seconds(1337) });
 
     // THEN
     expect(stack).to(haveResource('AWS::Route53::RecordSet', {
diff --git a/packages/@aws-cdk/aws-s3-deployment/lib/bucket-deployment.ts b/packages/@aws-cdk/aws-s3-deployment/lib/bucket-deployment.ts
index 77c427abfb8a3..833925ec9c6b7 100644
--- a/packages/@aws-cdk/aws-s3-deployment/lib/bucket-deployment.ts
+++ b/packages/@aws-cdk/aws-s3-deployment/lib/bucket-deployment.ts
@@ -49,7 +49,7 @@ export class BucketDeployment extends cdk.Construct {
       runtime: lambda.Runtime.Python36,
       handler: 'index.handler',
       lambdaPurpose: 'Custom::CDKBucketDeployment',
-      timeout: 15 * 60
+      timeout: cdk.Duration.minutes(15)
     });
 
     const source = props.source.bind(this);
diff --git a/packages/@aws-cdk/aws-s3/lib/bucket.ts b/packages/@aws-cdk/aws-s3/lib/bucket.ts
index b73d8725f32e9..6af7df69bae5c 100644
--- a/packages/@aws-cdk/aws-s3/lib/bucket.ts
+++ b/packages/@aws-cdk/aws-s3/lib/bucket.ts
@@ -875,7 +875,7 @@ export class Bucket extends BucketBase {
    * @param rule The rule to add
    */
   public addLifecycleRule(rule: LifecycleRule) {
-    if ((rule.noncurrentVersionExpirationInDays !== undefined
+    if ((rule.noncurrentVersionExpiration !== undefined
       || (rule.noncurrentVersionTransitions && rule.noncurrentVersionTransitions.length > 0))
       && !this.versioned) {
       throw new Error("Cannot use 'noncurrent' rules on a nonversioned bucket");
@@ -1061,17 +1061,24 @@ export class Bucket extends BucketBase {
     function parseLifecycleRule(rule: LifecycleRule): CfnBucket.RuleProperty {
       const enabled = rule.enabled !== undefined ? rule.enabled : true;
 
-      const x = {
+      const x: CfnBucket.RuleProperty = {
         // tslint:disable-next-line:max-line-length
-        abortIncompleteMultipartUpload: rule.abortIncompleteMultipartUploadAfterDays !== undefined ? { daysAfterInitiation: rule.abortIncompleteMultipartUploadAfterDays } : undefined,
+        abortIncompleteMultipartUpload: rule.abortIncompleteMultipartUploadAfter !== undefined ? { daysAfterInitiation: rule.abortIncompleteMultipartUploadAfter.toDays() } : undefined,
         expirationDate: rule.expirationDate,
-        expirationInDays: rule.expirationInDays,
+        expirationInDays: rule.expiration && rule.expiration.toDays(),
         id: rule.id,
-        noncurrentVersionExpirationInDays: rule.noncurrentVersionExpirationInDays,
-        noncurrentVersionTransitions: rule.noncurrentVersionTransitions,
+        noncurrentVersionExpirationInDays: rule.noncurrentVersionExpiration && rule.noncurrentVersionExpiration.toDays(),
+        noncurrentVersionTransitions: rule.noncurrentVersionTransitions && rule.noncurrentVersionTransitions.map(transition => ({
+          storageClass: transition.storageClass,
+          transitionInDays: transition.transitionAfter.toDays(),
+        })),
         prefix: rule.prefix,
         status: enabled ? 'Enabled' : 'Disabled',
-        transitions: rule.transitions,
+        transitions: rule.transitions && rule.transitions.map(transition => ({
+          storageClass: transition.storageClass,
+          transitionDate: transition.transitionDate,
+          transitionInDays: transition.transitionAfter && transition.transitionAfter.toDays(),
+        })),
         tagFilters: self.parseTagFilters(rule.tagFilters)
       };
 
diff --git a/packages/@aws-cdk/aws-s3/lib/rule.ts b/packages/@aws-cdk/aws-s3/lib/rule.ts
index 186469dd0048a..f629568c6eca4 100644
--- a/packages/@aws-cdk/aws-s3/lib/rule.ts
+++ b/packages/@aws-cdk/aws-s3/lib/rule.ts
@@ -1,3 +1,5 @@
+import { Duration } from "@aws-cdk/cdk";
+
 /**
  * Declaration of a Life cycle rule
  */
@@ -24,7 +26,7 @@ export interface LifecycleRule {
    *
    * @default Incomplete uploads are never aborted
    */
-  readonly abortIncompleteMultipartUploadAfterDays?: number;
+  readonly abortIncompleteMultipartUploadAfter?: Duration;
 
   /**
    * Indicates when objects are deleted from Amazon S3 and Amazon Glacier.
@@ -48,7 +50,7 @@ export interface LifecycleRule {
    *
    * @default No expiration timeout
    */
-  readonly expirationInDays?: number;
+  readonly expiration?: Duration;
 
   /**
    * Time between when a new version of the object is uploaded to the bucket and when old versions of the object expire.
@@ -62,7 +64,7 @@ export interface LifecycleRule {
    *
    * @default No noncurrent version expiration
    */
-  readonly noncurrentVersionExpirationInDays?: number;
+  readonly noncurrentVersionExpiration?: Duration;
 
   /**
    * One or more transition rules that specify when non-current objects transition to a specified storage class.
@@ -123,7 +125,7 @@ export interface Transition {
    *
    * @default No transition count.
    */
-  readonly transitionInDays?: number;
+  readonly transitionAfter?: Duration;
 }
 
 /**
@@ -140,7 +142,7 @@ export interface NoncurrentVersionTransition {
    *
    * @default No transition count.
    */
-  readonly transitionInDays: number;
+  readonly transitionAfter: Duration;
 }
 
 /**
diff --git a/packages/@aws-cdk/aws-s3/test/test.rules.ts b/packages/@aws-cdk/aws-s3/test/test.rules.ts
index 1724db63cd33f..d89064a556b1f 100644
--- a/packages/@aws-cdk/aws-s3/test/test.rules.ts
+++ b/packages/@aws-cdk/aws-s3/test/test.rules.ts
@@ -1,5 +1,5 @@
 import { expect, haveResource } from '@aws-cdk/assert';
-import { Stack } from '@aws-cdk/cdk';
+import { Duration, Stack } from '@aws-cdk/cdk';
 import { Test } from 'nodeunit';
 import { Bucket, StorageClass } from '../lib';
 
@@ -11,7 +11,7 @@ export = {
     // WHEN
     new Bucket(stack, 'Bucket', {
       lifecycleRules: [{
-        expirationInDays: 30
+        expiration: Duration.days(30)
       }]
     });
 
@@ -35,7 +35,7 @@ export = {
     // WHEN
     const bucket = new Bucket(stack, 'Bucket');
     bucket.addLifecycleRule({
-      expirationInDays: 30
+      expiration: Duration.days(30)
     });
 
     // THEN
@@ -84,7 +84,7 @@ export = {
       lifecycleRules: [{
         transitions: [{
           storageClass: StorageClass.Glacier,
-          transitionInDays: 30
+          transitionAfter: Duration.days(30)
         }]
       }]
     });
@@ -113,7 +113,7 @@ export = {
     test.throws(() => {
       new Bucket(stack, 'Bucket1', {
         lifecycleRules: [{
-          noncurrentVersionExpirationInDays: 10
+          noncurrentVersionExpiration: Duration.days(10)
         }]
       });
     });
@@ -122,7 +122,7 @@ export = {
     new Bucket(stack, 'Bucket2', {
       versioned: true,
       lifecycleRules: [{
-        noncurrentVersionExpirationInDays: 10
+        noncurrentVersionExpiration: Duration.days(10)
       }]
     });
 
diff --git a/packages/@aws-cdk/aws-secretsmanager/lib/rotation-schedule.ts b/packages/@aws-cdk/aws-secretsmanager/lib/rotation-schedule.ts
index f261707ba1dd8..d342817a861fc 100644
--- a/packages/@aws-cdk/aws-secretsmanager/lib/rotation-schedule.ts
+++ b/packages/@aws-cdk/aws-secretsmanager/lib/rotation-schedule.ts
@@ -1,5 +1,5 @@
 import lambda = require('@aws-cdk/aws-lambda');
-import { Construct, Resource } from '@aws-cdk/cdk';
+import { Construct, Duration, Resource } from '@aws-cdk/cdk';
 import { ISecret } from './secret';
 import { CfnRotationSchedule } from './secretsmanager.generated';
 
@@ -16,9 +16,9 @@ export interface RotationScheduleOptions {
    * Specifies the number of days after the previous rotation before
    * Secrets Manager triggers the next automatic rotation.
    *
-   * @default 30
+   * @default Duration.days(30)
    */
-  readonly automaticallyAfterDays?: number;
+  readonly automaticallyAfter?: Duration;
 }
 
 /**
@@ -42,7 +42,7 @@ export class RotationSchedule extends Resource {
       secretId: props.secret.secretArn,
       rotationLambdaArn: props.rotationLambda.functionArn,
       rotationRules: {
-        automaticallyAfterDays: props.automaticallyAfterDays || 30
+        automaticallyAfterDays: props.automaticallyAfter && props.automaticallyAfter.toDays() || 30
       }
     });
   }
diff --git a/packages/@aws-cdk/aws-servicediscovery/lib/service.ts b/packages/@aws-cdk/aws-servicediscovery/lib/service.ts
index 8188576b3929c..ae86ef72422b4 100644
--- a/packages/@aws-cdk/aws-servicediscovery/lib/service.ts
+++ b/packages/@aws-cdk/aws-servicediscovery/lib/service.ts
@@ -1,5 +1,5 @@
 import elbv2 = require('@aws-cdk/aws-elasticloadbalancingv2');
-import { Construct, IResource, Resource } from '@aws-cdk/cdk';
+import { Construct, Duration, IResource, Resource } from '@aws-cdk/cdk';
 import { AliasTargetInstance } from './alias-target-instance';
 import { CnameInstance, CnameInstanceBaseProps  } from './cname-instance';
 import { IInstance } from './instance';
@@ -98,9 +98,9 @@ export interface DnsServiceProps extends BaseServiceProps {
    * The amount of time, in seconds, that you want DNS resolvers to cache the settings for this
    * record.
    *
-   * @default 60
+   * @default Duration.minutes(1)
    */
-  readonly dnsTtlSec?: number;
+  readonly dnsTtl?: Duration;
 
   /**
    * The routing policy that you want to apply to all DNS records that AWS Cloud Map creates when you
@@ -248,7 +248,7 @@ export class Service extends ServiceBase {
     const dnsConfig: CfnService.DnsConfigProperty | undefined = props.namespace.type === NamespaceType.Http
       ? undefined
       : {
-          dnsRecords: renderDnsRecords(dnsRecordType, props.dnsTtlSec),
+          dnsRecords: renderDnsRecords(dnsRecordType, props.dnsTtl),
           namespaceId: props.namespace.namespaceId,
           routingPolicy,
         };
@@ -324,8 +324,8 @@ export class Service extends ServiceBase {
   }
 }
 
-function renderDnsRecords(dnsRecordType: DnsRecordType, dnsTtlSec?: number): CfnService.DnsRecordProperty[] {
-  const ttl = dnsTtlSec !== undefined ? dnsTtlSec : 60;
+function renderDnsRecords(dnsRecordType: DnsRecordType, dnsTtl: Duration = Duration.minutes(1)): CfnService.DnsRecordProperty[] {
+  const ttl = dnsTtl.toSeconds();
 
   if (dnsRecordType === DnsRecordType.A_AAAA) {
     return [{
diff --git a/packages/@aws-cdk/aws-servicediscovery/test/integ.service-with-cname-record.lit.ts b/packages/@aws-cdk/aws-servicediscovery/test/integ.service-with-cname-record.lit.ts
index 58b0adba8b412..10d8f50be29cc 100644
--- a/packages/@aws-cdk/aws-servicediscovery/test/integ.service-with-cname-record.lit.ts
+++ b/packages/@aws-cdk/aws-servicediscovery/test/integ.service-with-cname-record.lit.ts
@@ -11,7 +11,7 @@ const namespace = new servicediscovery.PublicDnsNamespace(stack, 'Namespace', {
 const service = namespace.createService('Service', {
   name: 'foo',
   dnsRecordType: servicediscovery.DnsRecordType.CNAME,
-  dnsTtlSec: 30
+  dnsTtl: cdk.Duration.seconds(30)
 });
 
 service.registerCnameInstance('CnameInstance', {
diff --git a/packages/@aws-cdk/aws-servicediscovery/test/integ.service-with-private-dns-namespace.lit.ts b/packages/@aws-cdk/aws-servicediscovery/test/integ.service-with-private-dns-namespace.lit.ts
index d785f0d960713..3aeecdc78abaf 100644
--- a/packages/@aws-cdk/aws-servicediscovery/test/integ.service-with-private-dns-namespace.lit.ts
+++ b/packages/@aws-cdk/aws-servicediscovery/test/integ.service-with-private-dns-namespace.lit.ts
@@ -15,7 +15,7 @@ const namespace = new servicediscovery.PrivateDnsNamespace(stack, 'Namespace', {
 
 const service = namespace.createService('Service', {
   dnsRecordType: servicediscovery.DnsRecordType.A_AAAA,
-  dnsTtlSec: 30,
+  dnsTtl: cdk.Duration.seconds(30),
   loadBalancer: true
 });
 
diff --git a/packages/@aws-cdk/aws-servicediscovery/test/integ.service-with-public-dns-namespace.lit.ts b/packages/@aws-cdk/aws-servicediscovery/test/integ.service-with-public-dns-namespace.lit.ts
index 43a997827b6d4..b1cd88a0e483b 100644
--- a/packages/@aws-cdk/aws-servicediscovery/test/integ.service-with-public-dns-namespace.lit.ts
+++ b/packages/@aws-cdk/aws-servicediscovery/test/integ.service-with-public-dns-namespace.lit.ts
@@ -11,7 +11,7 @@ const namespace = new servicediscovery.PublicDnsNamespace(stack, 'Namespace', {
 const service = namespace.createService('Service', {
   name: 'foo',
   dnsRecordType: servicediscovery.DnsRecordType.A,
-  dnsTtlSec: 30,
+  dnsTtl: cdk.Duration.seconds(30),
   healthCheck: {
     type: servicediscovery.HealthCheckType.Https,
     resourcePath: '/healthcheck',
diff --git a/packages/@aws-cdk/aws-sns/test/test.sns.ts b/packages/@aws-cdk/aws-sns/test/test.sns.ts
index 4447c45d5d2b9..ea109055a41e7 100644
--- a/packages/@aws-cdk/aws-sns/test/test.sns.ts
+++ b/packages/@aws-cdk/aws-sns/test/test.sns.ts
@@ -212,7 +212,7 @@ export = {
       dimensions: {TopicName: { 'Fn::GetAtt': [ 'TopicBFC7AF6E', 'TopicName' ] }},
       namespace: 'AWS/SNS',
       metricName: 'NumberOfMessagesPublished',
-      periodSec: 300,
+      period: cdk.Duration.minutes(5),
       statistic: 'Sum'
     });
 
@@ -220,7 +220,7 @@ export = {
       dimensions: {TopicName: { 'Fn::GetAtt': [ 'TopicBFC7AF6E', 'TopicName' ] }},
       namespace: 'AWS/SNS',
       metricName: 'PublishSize',
-      periodSec: 300,
+      period: cdk.Duration.minutes(5),
       statistic: 'Average'
     });
 
diff --git a/packages/@aws-cdk/aws-sqs/lib/queue.ts b/packages/@aws-cdk/aws-sqs/lib/queue.ts
index ad1a9bec47a12..374424264807f 100644
--- a/packages/@aws-cdk/aws-sqs/lib/queue.ts
+++ b/packages/@aws-cdk/aws-sqs/lib/queue.ts
@@ -1,5 +1,5 @@
 import kms = require('@aws-cdk/aws-kms');
-import { Construct, Stack } from '@aws-cdk/cdk';
+import { Construct, Duration, Stack, toSeconds } from '@aws-cdk/cdk';
 import { IQueue, QueueAttributes, QueueBase } from './queue-base';
 import { CfnQueue } from './sqs.generated';
 import { validateProps } from './validate-props';
@@ -23,9 +23,9 @@ export interface QueueProps {
    * You can specify an integer value from 60 seconds (1 minute) to 1209600
    * seconds (14 days). The default value is 345600 seconds (4 days).
    *
-   * @default 345600 seconds (4 days)
+   * @default Duration.days(4)
    */
-  readonly retentionPeriodSec?: number;
+  readonly retentionPeriod?: Duration;
 
   /**
    * The time in seconds that the delivery of all messages in the queue is delayed.
@@ -35,7 +35,7 @@ export interface QueueProps {
    *
    * @default 0
    */
-  readonly deliveryDelaySec?: number;
+  readonly deliveryDelay?: Duration;
 
   /**
    * The limit of how many bytes that a message can contain before Amazon SQS rejects it.
@@ -57,7 +57,7 @@ export interface QueueProps {
    *
    *  @default 0
    */
-  readonly receiveMessageWaitTimeSec?: number;
+  readonly receiveMessageWaitTime?: Duration;
 
   /**
    * Timeout of processing a single message.
@@ -69,9 +69,9 @@ export interface QueueProps {
    * Values must be from 0 to 43200 seconds (12 hours). If you don't specify
    * a value, AWS CloudFormation uses the default value of 30 seconds.
    *
-   * @default 30
+   * @default Duration.seconds(30)
    */
-  readonly visibilityTimeoutSec?: number;
+  readonly visibilityTimeout?: Duration;
 
   /**
    * Send messages to this queue if they were unsuccessfully dequeued a number of times.
@@ -111,9 +111,9 @@ export interface QueueProps {
    * The value must be an integer between 60 (1 minute) and 86,400 (24
    * hours). The default is 300 (5 minutes).
    *
-   * @default 300 (5 minutes)
+   * @default Duration.minutes(5)
    */
-  readonly dataKeyReuseSec?: number;
+  readonly dataKeyReuse?: Duration;
 
   /**
    * Whether this a first-in-first-out (FIFO) queue.
@@ -248,11 +248,11 @@ export class Queue extends QueueBase {
       ...this.determineFifoProps(props),
       ...encryptionProps,
       redrivePolicy,
-      delaySeconds: props.deliveryDelaySec,
+      delaySeconds: toSeconds(props.deliveryDelay),
       maximumMessageSize: props.maxMessageSizeBytes,
-      messageRetentionPeriod: props.retentionPeriodSec,
-      receiveMessageWaitTimeSeconds: props.receiveMessageWaitTimeSec,
-      visibilityTimeout: props.visibilityTimeoutSec,
+      messageRetentionPeriod: toSeconds(props.retentionPeriod),
+      receiveMessageWaitTimeSeconds: toSeconds(props.receiveMessageWaitTime),
+      visibilityTimeout: toSeconds(props.visibilityTimeout),
     });
     this.encryptionMasterKey = encryptionMasterKey;
     this.queueArn = queue.queueArn;
@@ -277,7 +277,7 @@ export class Queue extends QueueBase {
           encryptionMasterKey: masterKey,
           encryptionProps: {
             kmsMasterKeyId: 'alias/aws/sqs',
-            kmsDataKeyReusePeriodSeconds: props.dataKeyReuseSec
+            kmsDataKeyReusePeriodSeconds: props.dataKeyReuse && props.dataKeyReuse.toSeconds()
           }
         };
       }
@@ -291,7 +291,7 @@ export class Queue extends QueueBase {
           encryptionMasterKey: masterKey,
           encryptionProps: {
             kmsMasterKeyId: masterKey.keyArn,
-            kmsDataKeyReusePeriodSeconds: props.dataKeyReuseSec
+            kmsDataKeyReusePeriodSeconds: props.dataKeyReuse && props.dataKeyReuse.toSeconds()
           }
         };
       }
diff --git a/packages/@aws-cdk/aws-sqs/lib/validate-props.ts b/packages/@aws-cdk/aws-sqs/lib/validate-props.ts
index ecebbde44d42c..45bf28894e084 100644
--- a/packages/@aws-cdk/aws-sqs/lib/validate-props.ts
+++ b/packages/@aws-cdk/aws-sqs/lib/validate-props.ts
@@ -1,11 +1,12 @@
+import { toSeconds } from '@aws-cdk/cdk';
 import { QueueProps } from './index';
 
 export function validateProps(props: QueueProps) {
-  validateRange('delivery delay', props.deliveryDelaySec, 0, 900, 'seconds');
+  validateRange('delivery delay', toSeconds(props.deliveryDelay), 0, 900, 'seconds');
   validateRange('maximum message size', props.maxMessageSizeBytes, 1_024, 262_144, 'bytes');
-  validateRange('message retention period', props.retentionPeriodSec, 60, 1_209_600, 'seconds');
-  validateRange('receive wait time', props.receiveMessageWaitTimeSec, 0, 20, 'seconds');
-  validateRange('visibility timeout', props.visibilityTimeoutSec, 0, 43_200, 'seconds');
+  validateRange('message retention period', toSeconds(props.retentionPeriod), 60, 1_209_600, 'seconds');
+  validateRange('receive wait time', toSeconds(props.receiveMessageWaitTime), 0, 20, 'seconds');
+  validateRange('visibility timeout', toSeconds(props.visibilityTimeout), 0, 43_200, 'seconds');
   validateRange('dead letter target maximum receive count', props.deadLetterQueue && props.deadLetterQueue.maxReceiveCount, 1, +Infinity);
 }
 
diff --git a/packages/@aws-cdk/aws-sqs/test/test.sqs.ts b/packages/@aws-cdk/aws-sqs/test/test.sqs.ts
index 18c22edfcba05..ee99f1e83b0ba 100644
--- a/packages/@aws-cdk/aws-sqs/test/test.sqs.ts
+++ b/packages/@aws-cdk/aws-sqs/test/test.sqs.ts
@@ -1,7 +1,7 @@
 import { expect, haveResource } from '@aws-cdk/assert';
 import iam = require('@aws-cdk/aws-iam');
 import kms = require('@aws-cdk/aws-kms');
-import { Stack } from '@aws-cdk/cdk';
+import { Duration, Stack } from '@aws-cdk/cdk';
 import { Test } from 'nodeunit';
 import sqs = require('../lib');
 import { Queue } from '../lib';
@@ -281,7 +281,7 @@ export = {
       dimensions: {QueueName: { 'Fn::GetAtt': [ 'Queue4A7E3555', 'QueueName' ] }},
       namespace: 'AWS/SQS',
       metricName: 'NumberOfMessagesSent',
-      periodSec: 300,
+      period: Duration.minutes(5),
       statistic: 'Sum'
     });
 
@@ -289,7 +289,7 @@ export = {
       dimensions: {QueueName: { 'Fn::GetAtt': [ 'Queue4A7E3555', 'QueueName' ] }},
       namespace: 'AWS/SQS',
       metricName: 'SentMessageSize',
-      periodSec: 300,
+      period: Duration.minutes(5),
       statistic: 'Average'
     });
 
diff --git a/packages/@aws-cdk/aws-stepfunctions-tasks/lib/invoke-activity.ts b/packages/@aws-cdk/aws-stepfunctions-tasks/lib/invoke-activity.ts
index c9ebca5c49f24..910ca332e9f7e 100644
--- a/packages/@aws-cdk/aws-stepfunctions-tasks/lib/invoke-activity.ts
+++ b/packages/@aws-cdk/aws-stepfunctions-tasks/lib/invoke-activity.ts
@@ -1,4 +1,5 @@
 import sfn = require('@aws-cdk/aws-stepfunctions');
+import { Duration } from '@aws-cdk/cdk';
 
 /**
  * Properties for FunctionTask
@@ -11,7 +12,7 @@ export interface InvokeActivityProps {
    *
    * @default No heart beat timeout
    */
-  readonly heartbeatSeconds?: number;
+  readonly heartbeat?: Duration;
 }
 
 /**
@@ -28,7 +29,7 @@ export class InvokeActivity implements sfn.IStepFunctionsTask {
     return {
       resourceArn: this.activity.activityArn,
       metricDimensions: { ActivityArn: this.activity.activityArn },
-      heartbeatSeconds: this.props.heartbeatSeconds,
+      heartbeat: this.props.heartbeat,
       // No IAM permissions necessary, execution role implicitly has Activity permissions.
       metricPrefixSingular: 'Activity',
       metricPrefixPlural: 'Activities',
diff --git a/packages/@aws-cdk/aws-stepfunctions-tasks/lib/send-to-queue.ts b/packages/@aws-cdk/aws-stepfunctions-tasks/lib/send-to-queue.ts
index ce10c26947cfc..87c3075371a10 100644
--- a/packages/@aws-cdk/aws-stepfunctions-tasks/lib/send-to-queue.ts
+++ b/packages/@aws-cdk/aws-stepfunctions-tasks/lib/send-to-queue.ts
@@ -1,6 +1,7 @@
 import iam = require('@aws-cdk/aws-iam');
 import sqs = require('@aws-cdk/aws-sqs');
 import sfn = require('@aws-cdk/aws-stepfunctions');
+import { Duration, toSeconds } from '@aws-cdk/cdk';
 
 /**
  * Properties for SendMessageTask
@@ -18,7 +19,7 @@ export interface SendToQueueProps {
    *
    * @default Default value of the queue is used
    */
-  readonly delaySeconds?: number;
+  readonly delay?: Duration;
 
   /**
    * The token used for deduplication of sent messages.
@@ -59,7 +60,7 @@ export class SendToQueue implements sfn.IStepFunctionsTask {
         QueueUrl: this.queue.queueUrl,
         ...sfn.FieldUtils.renderObject({
           MessageBody: this.props.messageBody.value,
-          DelaySeconds: this.props.delaySeconds,
+          DelaySeconds: toSeconds(this.props.delay),
           MessageDeduplicationId: this.props.messageDeduplicationId,
           MessageGroupId: this.props.messageGroupId,
         })
diff --git a/packages/@aws-cdk/aws-stepfunctions-tasks/test/integ.job-poller.ts b/packages/@aws-cdk/aws-stepfunctions-tasks/test/integ.job-poller.ts
index 5fae9e8d1819b..5f7f9db9d731f 100644
--- a/packages/@aws-cdk/aws-stepfunctions-tasks/test/integ.job-poller.ts
+++ b/packages/@aws-cdk/aws-stepfunctions-tasks/test/integ.job-poller.ts
@@ -13,7 +13,7 @@ class JobPollerStack extends cdk.Stack {
             task: new tasks.InvokeActivity(submitJobActivity),
             resultPath: '$.guid',
         });
-        const waitX = new sfn.Wait(this, 'Wait X Seconds', { duration: sfn.WaitDuration.secondsPath('$.wait_time') });
+        const waitX = new sfn.Wait(this, 'Wait X Seconds', { time: sfn.WaitTime.secondsPath('$.wait_time') });
         const getStatus = new sfn.Task(this, 'Get Job Status', {
             task: new tasks.InvokeActivity(checkJobActivity),
             inputPath: '$.guid',
@@ -40,11 +40,11 @@ class JobPollerStack extends cdk.Stack {
 
         new sfn.StateMachine(this, 'StateMachine', {
             definition: chain,
-            timeoutSec: 30
+            timeout: cdk.Duration.seconds(30)
         });
     }
 }
 
 const app = new cdk.App();
 new JobPollerStack(app, 'aws-stepfunctions-integ');
-app.synth();
\ No newline at end of file
+app.synth();
diff --git a/packages/@aws-cdk/aws-stepfunctions/README.md b/packages/@aws-cdk/aws-stepfunctions/README.md
index 0bb4278c64659..be9ccb1a1da14 100644
--- a/packages/@aws-cdk/aws-stepfunctions/README.md
+++ b/packages/@aws-cdk/aws-stepfunctions/README.md
@@ -70,7 +70,7 @@ const definition = submitJob
 
 new sfn.StateMachine(this, 'StateMachine', {
     definition,
-    timeoutSec: 300
+    timeout: Duration.minutes(5)
 });
 ```
 
@@ -143,12 +143,12 @@ similar to (for example) `inputPath`.
 const task = new sfn.Task(this, 'Invoke The Lambda', {
     task: new tasks.InvokeFunction(myLambda),
     inputPath: '$.input',
-    timeoutSeconds: 300,
+    timeout: Duration.minutes(5),
 });
 
 // Add a retry policy
 task.addRetry({
-    intervalSeconds: 5,
+    interval: Duration.seconds(5),
     maxAttempts: 10
 });
 
diff --git a/packages/@aws-cdk/aws-stepfunctions/lib/state-graph.ts b/packages/@aws-cdk/aws-stepfunctions/lib/state-graph.ts
index 50d368493ce63..00f13f69da502 100644
--- a/packages/@aws-cdk/aws-stepfunctions/lib/state-graph.ts
+++ b/packages/@aws-cdk/aws-stepfunctions/lib/state-graph.ts
@@ -1,4 +1,5 @@
 import iam = require('@aws-cdk/aws-iam');
+import { Duration } from '@aws-cdk/cdk';
 import { State } from "./states/state";
 
 /**
@@ -32,7 +33,7 @@ export class StateGraph {
      *
      * @default No timeout
      */
-    public timeoutSeconds?: number;
+    public timeout?: Duration;
 
     /**
      * The accumulated policy statements
@@ -107,7 +108,7 @@ export class StateGraph {
         return {
             StartAt: this.startState.stateId,
             States: states,
-            TimeoutSeconds: this.timeoutSeconds
+            TimeoutSeconds: this.timeout && this.timeout.toSeconds()
         };
     }
 
@@ -154,4 +155,4 @@ export class StateGraph {
         }
     }
 
-}
\ No newline at end of file
+}
diff --git a/packages/@aws-cdk/aws-stepfunctions/lib/state-machine.ts b/packages/@aws-cdk/aws-stepfunctions/lib/state-machine.ts
index 2341cd8beb1a7..824bc8d8a5333 100644
--- a/packages/@aws-cdk/aws-stepfunctions/lib/state-machine.ts
+++ b/packages/@aws-cdk/aws-stepfunctions/lib/state-machine.ts
@@ -1,6 +1,6 @@
 import cloudwatch = require('@aws-cdk/aws-cloudwatch');
 import iam = require('@aws-cdk/aws-iam');
-import { Construct, IResource, Resource, Stack } from '@aws-cdk/cdk';
+import { Construct, Duration, IResource, Resource, Stack } from '@aws-cdk/cdk';
 import { StateGraph } from './state-graph';
 import { CfnStateMachine } from './stepfunctions.generated';
 import { IChainable } from './types';
@@ -33,7 +33,7 @@ export interface StateMachineProps {
      *
      * @default No timeout
      */
-    readonly timeoutSec?: number;
+    readonly timeout?: Duration;
 }
 
 /**
@@ -94,7 +94,7 @@ export class StateMachine extends StateMachineBase {
         });
 
         const graph = new StateGraph(props.definition.startState, `State Machine ${id} definition`);
-        graph.timeoutSeconds = props.timeoutSec;
+        graph.timeout = props.timeout;
 
         const resource = new CfnStateMachine(this, 'Resource', {
             stateMachineName: props.stateMachineName,
diff --git a/packages/@aws-cdk/aws-stepfunctions/lib/states/state.ts b/packages/@aws-cdk/aws-stepfunctions/lib/states/state.ts
index 5dce6925b53d7..2b333b91e3e43 100644
--- a/packages/@aws-cdk/aws-stepfunctions/lib/states/state.ts
+++ b/packages/@aws-cdk/aws-stepfunctions/lib/states/state.ts
@@ -437,7 +437,7 @@ interface CatchTransition {
 function renderRetry(retry: RetryProps) {
     return {
         ErrorEquals: retry.errors,
-        IntervalSeconds: retry.intervalSeconds,
+        IntervalSeconds: cdk.toSeconds(retry.interval),
         MaxAttempts: retry.maxAttempts,
         BackoffRate: retry.backoffRate
     };
@@ -507,4 +507,4 @@ export enum StateType {
     Succeed = 'Succeed',
     Fail = 'Fail',
     Parallel = 'Parallel'
-}
\ No newline at end of file
+}
diff --git a/packages/@aws-cdk/aws-stepfunctions/lib/states/task.ts b/packages/@aws-cdk/aws-stepfunctions/lib/states/task.ts
index e39fd94561b83..10b41d3c7f37b 100644
--- a/packages/@aws-cdk/aws-stepfunctions/lib/states/task.ts
+++ b/packages/@aws-cdk/aws-stepfunctions/lib/states/task.ts
@@ -59,7 +59,7 @@ export interface TaskProps {
      *
      * @default 60
      */
-    readonly timeoutSeconds?: number;
+    readonly timeout?: cdk.Duration;
 }
 
 /**
@@ -74,13 +74,13 @@ export interface TaskProps {
  */
 export class Task extends State implements INextable {
     public readonly endStates: INextable[];
-    private readonly timeoutSeconds?: number;
+    private readonly timeout?: cdk.Duration;
     private readonly taskProps: StepFunctionsTaskConfig;
 
     constructor(scope: cdk.Construct, id: string, props: TaskProps) {
         super(scope, id, props);
 
-        this.timeoutSeconds = props.timeoutSeconds;
+        this.timeout = props.timeout;
         this.taskProps = props.task.bind(this);
         this.endStates = [this];
     }
@@ -128,8 +128,8 @@ export class Task extends State implements INextable {
             Resource: this.taskProps.resourceArn,
             Parameters: this.taskProps.parameters,
             ResultPath: renderJsonPath(this.resultPath),
-            TimeoutSeconds: this.timeoutSeconds,
-            HeartbeatSeconds: this.taskProps.heartbeatSeconds,
+            TimeoutSeconds: cdk.toSeconds(this.timeout),
+            HeartbeatSeconds: cdk.toSeconds(this.taskProps.heartbeat),
         };
     }
 
diff --git a/packages/@aws-cdk/aws-stepfunctions/lib/states/wait.ts b/packages/@aws-cdk/aws-stepfunctions/lib/states/wait.ts
index 608714ad80c1b..87be700236972 100644
--- a/packages/@aws-cdk/aws-stepfunctions/lib/states/wait.ts
+++ b/packages/@aws-cdk/aws-stepfunctions/lib/states/wait.ts
@@ -3,32 +3,32 @@ import { Chain } from '../chain';
 import { IChainable, INextable } from '../types';
 import { State, StateType } from './state';
 
-export class WaitDuration {
+export class WaitTime {
     /**
-     * Wait a fixed number of seconds
+     * Wait a fixed amount of time.
      */
-    public static seconds(duration: number) { return new WaitDuration({ Seconds: duration }); }
+    public static duration(duration: cdk.Duration) { return new WaitTime({ Seconds: duration.toSeconds() }); }
 
     /**
      * Wait until the given ISO8601 timestamp
      *
      * @example 2016-03-14T01:59:00Z
      */
-    public static timestamp(timestamp: string) { return new WaitDuration({ Timestamp: timestamp }); }
+    public static timestamp(timestamp: string) { return new WaitTime({ Timestamp: timestamp }); }
 
     /**
      * Wait for a number of seconds stored in the state object.
      *
      * @example $.waitSeconds
      */
-    public static secondsPath(path: string) { return new WaitDuration({ SecondsPath: path }); }
+    public static secondsPath(path: string) { return new WaitTime({ SecondsPath: path }); }
 
     /**
      * Wait until a timestamp found in the state object.
      *
      * @example $.waitTimestamp
      */
-    public static timestampPath(path: string) { return new WaitDuration({ TimestampPath: path }); }
+    public static timestampPath(path: string) { return new WaitTime({ TimestampPath: path }); }
 
     private constructor(private readonly json: any) { }
 
@@ -54,7 +54,7 @@ export interface WaitProps {
     /**
      * Wait duration.
      */
-    readonly duration: WaitDuration;
+    readonly time: WaitTime;
 }
 
 /**
@@ -65,12 +65,12 @@ export interface WaitProps {
 export class Wait extends State implements INextable {
     public readonly endStates: INextable[];
 
-    private readonly duration: WaitDuration;
+    private readonly time: WaitTime;
 
     constructor(scope: cdk.Construct, id: string, props: WaitProps) {
         super(scope, id, props);
 
-        this.duration = props.duration;
+        this.time = props.time;
         this.endStates = [this];
     }
 
@@ -89,8 +89,8 @@ export class Wait extends State implements INextable {
         return {
             Type: StateType.Wait,
             Comment: this.comment,
-            ...this.duration._json,
+            ...this.time._json,
             ...this.renderNextEnd(),
         };
     }
-}
\ No newline at end of file
+}
diff --git a/packages/@aws-cdk/aws-stepfunctions/lib/step-functions-task.ts b/packages/@aws-cdk/aws-stepfunctions/lib/step-functions-task.ts
index 6a7a756df74b0..a8dabc6658f54 100644
--- a/packages/@aws-cdk/aws-stepfunctions/lib/step-functions-task.ts
+++ b/packages/@aws-cdk/aws-stepfunctions/lib/step-functions-task.ts
@@ -1,5 +1,6 @@
 import cloudwatch = require('@aws-cdk/aws-cloudwatch');
 import iam = require('@aws-cdk/aws-iam');
+import { Duration } from '@aws-cdk/cdk';
 import { Task } from './states/task';
 
 /**
@@ -47,7 +48,7 @@ export interface StepFunctionsTaskConfig {
    *
    * @default No heart beat timeout
    */
-  readonly heartbeatSeconds?: number;
+  readonly heartbeat?: Duration;
 
   /**
    * Additional policy statements to add to the execution role
diff --git a/packages/@aws-cdk/aws-stepfunctions/lib/types.ts b/packages/@aws-cdk/aws-stepfunctions/lib/types.ts
index b6e19a127ba98..5116c0382db38 100644
--- a/packages/@aws-cdk/aws-stepfunctions/lib/types.ts
+++ b/packages/@aws-cdk/aws-stepfunctions/lib/types.ts
@@ -1,3 +1,4 @@
+import { Duration } from '@aws-cdk/cdk';
 import { Chain } from './chain';
 import { State } from './states/state';
 
@@ -93,9 +94,9 @@ export interface RetryProps {
     /**
      * How many seconds to wait initially before retrying
      *
-     * @default 1
+     * @default Duration.seconds(1)
      */
-    readonly intervalSeconds?: number;
+    readonly interval?: Duration;
 
     /**
      * How many times to retry this particular error.
@@ -143,4 +144,4 @@ export interface CatchProps {
 /**
  * Special string value to discard state input, output or result
  */
-export const DISCARD = 'DISCARD';
\ No newline at end of file
+export const DISCARD = 'DISCARD';
diff --git a/packages/@aws-cdk/aws-stepfunctions/package.json b/packages/@aws-cdk/aws-stepfunctions/package.json
index cb731048b7467..055110331c074 100644
--- a/packages/@aws-cdk/aws-stepfunctions/package.json
+++ b/packages/@aws-cdk/aws-stepfunctions/package.json
@@ -88,8 +88,10 @@
   "awslint": {
     "exclude": [
       "import-props-interface:@aws-cdk/aws-stepfunctions.ActivityImportProps",
-      "export:@aws-cdk/aws-stepfunctions.IActivity"
+      "export:@aws-cdk/aws-stepfunctions.IActivity",
+      "duration-prop-type:@aws-cdk/aws-stepfunctions.WaitProps.duration",
+      "duration-prop-type:@aws-cdk/aws-stepfunctions.Errors.Timeout"
     ]
   },
   "stability": "experimental"
-}
\ No newline at end of file
+}
diff --git a/packages/@aws-cdk/aws-stepfunctions/test/test.activity.ts b/packages/@aws-cdk/aws-stepfunctions/test/test.activity.ts
index 5b45bdee74467..f0775cc2e4168 100644
--- a/packages/@aws-cdk/aws-stepfunctions/test/test.activity.ts
+++ b/packages/@aws-cdk/aws-stepfunctions/test/test.activity.ts
@@ -28,7 +28,7 @@ export = {
 
         // THEN
         const sharedMetric = {
-            periodSec: 300,
+            period: cdk.Duration.minutes(5),
             namespace: 'AWS/States',
             dimensions: { ActivityArn: { Ref: 'Activity04690B0A' }},
         };
@@ -46,4 +46,4 @@ export = {
 
         test.done();
     }
-};
\ No newline at end of file
+};
diff --git a/packages/@aws-cdk/aws-stepfunctions/test/test.states-language.ts b/packages/@aws-cdk/aws-stepfunctions/test/test.states-language.ts
index edc794c6f126b..a4c2d50e5c45b 100644
--- a/packages/@aws-cdk/aws-stepfunctions/test/test.states-language.ts
+++ b/packages/@aws-cdk/aws-stepfunctions/test/test.states-language.ts
@@ -102,7 +102,9 @@ export = {
 
             const task1 = new stepfunctions.Pass(stack, 'State One');
             const task2 = new stepfunctions.Pass(stack, 'State Two');
-            const task3 = new stepfunctions.Wait(stack, 'State Three', { duration: stepfunctions.WaitDuration.seconds(10) });
+            const task3 = new stepfunctions.Wait(stack, 'State Three', {
+                time: stepfunctions.WaitTime.duration(cdk.Duration.seconds(10))
+            });
 
             // WHEN
             const chain = stepfunctions.Chain
diff --git a/packages/@aws-cdk/cdk/lib/cfn-resource.ts b/packages/@aws-cdk/cdk/lib/cfn-resource.ts
index 38317256cf8f3..253dd2a8153ce 100644
--- a/packages/@aws-cdk/cdk/lib/cfn-resource.ts
+++ b/packages/@aws-cdk/cdk/lib/cfn-resource.ts
@@ -222,7 +222,7 @@ export class CfnResource extends CfnRefElement {
             Type: this.resourceType,
             Properties: ignoreEmpty(properties),
             DependsOn: ignoreEmpty(renderDependsOn(this.dependsOn)),
-            CreationPolicy:  capitalizePropertyNames(this, this.options.creationPolicy),
+            CreationPolicy:  capitalizePropertyNames(this, renderCreationPolicy(this.options.creationPolicy)),
             UpdatePolicy: capitalizePropertyNames(this, this.options.updatePolicy),
             UpdateReplacePolicy: capitalizePropertyNames(this, this.options.updateReplacePolicy),
             DeletionPolicy: capitalizePropertyNames(this, this.options.deletionPolicy),
@@ -261,6 +261,18 @@ export class CfnResource extends CfnRefElement {
         .sort((x, y) => x.node.path.localeCompare(y.node.path))
         .map(r => r.logicalId);
     }
+
+    function renderCreationPolicy(policy: CreationPolicy | undefined): any {
+      if (!policy) { return undefined; }
+      const result: any = { ...policy };
+      if (policy.resourceSignal && policy.resourceSignal.timeout) {
+        result.resourceSignal = {
+          ...policy.resourceSignal,
+          timeout: policy.resourceSignal.timeout.toISOString(),
+        };
+      }
+      return result;
+    }
   }
 
   protected renderProperties(properties: any): { [key: string]: any } {
diff --git a/packages/@aws-cdk/cdk/lib/duration.ts b/packages/@aws-cdk/cdk/lib/duration.ts
new file mode 100644
index 0000000000000..d8d8ca7f23a3e
--- /dev/null
+++ b/packages/@aws-cdk/cdk/lib/duration.ts
@@ -0,0 +1,208 @@
+/**
+ * Represents a length of time.
+ */
+export class Duration {
+  /**
+   * @param amount the amount of Seconds the `Duration` will represent.
+   * @returns a new `Duration` representing `amount` Seconds.
+   */
+  public static seconds(amount: number): Duration {
+    return new Duration(amount, TimeUnit.Seconds);
+  }
+
+  /**
+   * @param amount the amount of Minutes the `Duration` will represent.
+   * @returns a new `Duration` representing `amount` Minutes.
+   */
+  public static minutes(amount: number): Duration {
+    return new Duration(amount, TimeUnit.Minutes);
+  }
+
+  /**
+   * @param amount the amount of Hours the `Duration` will represent.
+   * @returns a new `Duration` representing `amount` Hours.
+   */
+  public static hours(amount: number): Duration {
+    return new Duration(amount, TimeUnit.Hours);
+  }
+
+  /**
+   * @param amount the amount of Days the `Duration` will represent.
+   * @returns a new `Duration` representing `amount` Days.
+   */
+  public static days(amount: number): Duration {
+    return new Duration(amount, TimeUnit.Days);
+  }
+
+  /**
+   * @param duration an ISO-formtted duration to be parsed.
+   * @returns the parsed `Duration`.
+   */
+  public static parse(duration: string): Duration {
+    const matches = duration.match(/^PT(?:(\d+)D)?(?:(\d+)H)?(?:(\d+)M)?(?:(\d+)S)?$/);
+    if (!matches) {
+      throw new Error(`Not a valid ISO duration: ${duration}`);
+    }
+    const [, days, hours, minutes, seconds] = matches;
+    if (!days && !hours && !minutes && !seconds) {
+      throw new Error(`Not a valid ISO duration: ${duration}`);
+    }
+    return Duration.seconds(
+      _toInt(seconds)
+      + (_toInt(minutes) * 60)
+      + (_toInt(hours) * 3_600)
+      + (_toInt(days) * 86_400)
+    );
+
+    function _toInt(str: string): number {
+      if (!str) { return 0; }
+      return Number(str);
+    }
+  }
+
+  private readonly amount: number;
+  private readonly unit: TimeUnit;
+
+  private constructor(amount: number, unit: TimeUnit) {
+    if (amount < 0) {
+      throw new Error(`Duration amounts cannot be negative. Received: ${amount}`);
+    }
+
+    this.amount = amount;
+    this.unit = unit;
+  }
+
+  /**
+   * @returns the value of this `Duration` expressed in Seconds.
+   */
+  public toSeconds(_opts: TimeConversionOptions = {}): number {
+    switch (this.unit) {
+      case TimeUnit.Seconds:
+        return this.amount;
+      case TimeUnit.Minutes:
+        return this.amount * 60;
+      case TimeUnit.Hours:
+        return this.amount * 3600;
+      case TimeUnit.Days:
+        return this.amount * 86_400;
+      default:
+        throw new Error(`Unexpected time unit: ${this.unit}`);
+    }
+  }
+
+  public toMinutes(opts: TimeConversionOptions = {}): number {
+    switch (this.unit) {
+      case TimeUnit.Seconds:
+        return this.safeConversion(60, opts, TimeUnit.Seconds);
+      case TimeUnit.Minutes:
+        return this.amount;
+      case TimeUnit.Hours:
+        return this.amount * 60;
+      case TimeUnit.Days:
+        return this.amount * 1_440;
+      default:
+        throw new Error(`Unexpected time unit: ${this.unit}`);
+    }
+  }
+
+  /**
+   * @returns the value of this `Duration` expressed in Days.
+   */
+  public toDays(opts: TimeConversionOptions = {}): number {
+    switch (this.unit) {
+      case TimeUnit.Seconds:
+        return this.safeConversion(86_400, opts, TimeUnit.Days);
+      case TimeUnit.Minutes:
+        return this.safeConversion(1_440, opts, TimeUnit.Days);
+      case TimeUnit.Hours:
+        return this.safeConversion(24, opts, TimeUnit.Days);
+      case TimeUnit.Days:
+        return this.amount;
+      default:
+        throw new Error(`Unexpected time unit: ${this.unit}`);
+    }
+  }
+
+  /**
+   * @returns ISO representation of this period.
+   */
+  public toISOString(): string {
+    if (this.amount === 0) { return 'PT0S'; }
+    switch (this.unit) {
+      case TimeUnit.Seconds:
+        return `PT${this.fractionDuration('S', 60, Duration.minutes)}`;
+      case TimeUnit.Minutes:
+        return `PT${this.fractionDuration('M', 60, Duration.hours)}`;
+      case TimeUnit.Hours:
+        return `PT${this.fractionDuration('H', 24, Duration.days)}`;
+      case TimeUnit.Days:
+        return `PT${this.amount}D`;
+      default:
+        throw new Error(`Unexpected time unit: ${this.unit}`);
+    }
+  }
+
+  public toString(): string {
+    return `${this.amount} ${this.unit}`;
+  }
+
+  /**
+   * Divides the current duration by a certain amount and throws an exception if `opts` requires `integral` conversion
+   * and the requirement is not satisfied.
+   *
+   * @param divisor    the value to divide `this.amount` by.
+   * @param opts       conversion options instructing whether integral conversion is required or not.
+   * @param targetUnit the unit of time we are converting to, so it can be used in the error message when needed
+   *
+   * @returns the result of `this.amount / divisor`.
+   */
+  private safeConversion(divisor: number, { integral = true }: TimeConversionOptions, targetUnit: TimeUnit): number {
+    const remainder = this.amount % divisor;
+    if (integral && remainder !== 0) {
+      throw new Error(`Impossible intergal conversion of ${this} to ${targetUnit} was requested`);
+    }
+    return this.amount / divisor;
+  }
+
+  private fractionDuration(symbol: string, modulus: number, next: (amount: number) => Duration): string {
+    if (this.amount < modulus) {
+      return `${this.amount}${symbol}`;
+    }
+    const remainder = this.amount % modulus;
+    const quotient = next((this.amount - remainder) / modulus).toISOString().slice(2);
+    return remainder > 0
+      ? `${quotient}${remainder}${symbol}`
+      : quotient;
+  }
+}
+
+/**
+ * Options for how to convert time to a different unit.
+ */
+export interface TimeConversionOptions {
+  /**
+   * If `true`, conversions into a larger time unit (e.g. `Seconds` to `Mintues`) will fail if the result is not an
+   * integer.
+   *
+   * @default true
+   */
+  readonly integral?: boolean;
+}
+
+const enum TimeUnit {
+  Seconds = 's',
+  Minutes = 'minutes',
+  Hours = 'hours',
+  Days = 'days'
+}
+
+/**
+ * Helpful syntax sugar for turning an optional `Duration` into a count of seconds.
+ *
+ * @param duration an optional duration to convert into an amount of sunctions.
+ *
+ * @return `duration && duration.toSeconds()`.
+ */
+export function toSeconds(duration: Duration | undefined): number | undefined {
+  return duration && duration.toSeconds();
+}
diff --git a/packages/@aws-cdk/cdk/lib/index.ts b/packages/@aws-cdk/cdk/lib/index.ts
index bc99eb685e1cf..657afc156b982 100644
--- a/packages/@aws-cdk/cdk/lib/index.ts
+++ b/packages/@aws-cdk/cdk/lib/index.ts
@@ -27,6 +27,7 @@ export * from './cfn-dynamic-reference';
 export * from './tag';
 export * from './removal-policy';
 export * from './arn';
+export * from './duration';
 
 export * from './app';
 export * from './context';
diff --git a/packages/@aws-cdk/cdk/lib/resource-policy.ts b/packages/@aws-cdk/cdk/lib/resource-policy.ts
index a3ff6b9d84691..20bc69c8f8d42 100644
--- a/packages/@aws-cdk/cdk/lib/resource-policy.ts
+++ b/packages/@aws-cdk/cdk/lib/resource-policy.ts
@@ -1,3 +1,5 @@
+import { Duration } from "./duration";
+
 /**
  * Associate the CreationPolicy attribute with a resource to prevent its status from reaching create complete until
  * AWS CloudFormation receives a specified number of success signals or the timeout period is exceeded. To signal a
@@ -61,7 +63,7 @@ export interface ResourceSignal {
    * The timeout period starts after AWS CloudFormation starts creating the resource, and the timeout expires no sooner
    * than the time you specify but can occur shortly thereafter. The maximum time that you can specify is 12 hours.
    */
-  readonly timeout?: string;
+  readonly timeout?: Duration;
 }
 
 /**
diff --git a/packages/@aws-cdk/cdk/test/test.duration.ts b/packages/@aws-cdk/cdk/test/test.duration.ts
new file mode 100644
index 0000000000000..7996d7fc86e73
--- /dev/null
+++ b/packages/@aws-cdk/cdk/test/test.duration.ts
@@ -0,0 +1,91 @@
+import nodeunit = require('nodeunit');
+import { Duration } from '../lib';
+
+export = nodeunit.testCase({
+  'negative amount'(test: nodeunit.Test) {
+    test.throws(() => Duration.seconds(-1), /negative/);
+
+    test.done();
+  },
+
+  'Duration in seconds'(test: nodeunit.Test) {
+    const duration = Duration.seconds(300);
+
+    test.equal(duration.toSeconds(), 300);
+    test.equal(duration.toMinutes(), 5);
+    test.throws(() => duration.toDays(), /Impossible intergal conversion of/);
+    test.equal(duration.toDays({ integral: false }), 300 / 86_400);
+
+    test.equal(Duration.seconds(60 * 60 * 24).toDays(), 1);
+
+    test.done();
+  },
+
+  'Duration in minutes'(test: nodeunit.Test) {
+    const duration = Duration.minutes(5);
+
+    test.equal(duration.toSeconds(), 300);
+    test.equal(duration.toMinutes(), 5);
+    test.throws(() => duration.toDays(), /Impossible intergal conversion of/);
+    test.equal(duration.toDays({ integral: false }), 300 / 86_400);
+
+    test.equal(Duration.minutes(60 * 24).toDays(), 1);
+
+    test.done();
+  },
+
+  'Duration in hours'(test: nodeunit.Test) {
+    const duration = Duration.hours(5);
+
+    test.equal(duration.toSeconds(), 18_000);
+    test.equal(duration.toMinutes(), 300);
+    test.throws(() => duration.toDays(), /Impossible intergal conversion of/);
+    test.equals(duration.toDays({ integral: false }), 5 / 24);
+
+    test.equal(Duration.hours(24).toDays(), 1);
+
+    test.done();
+  },
+
+  'Duration in days'(test: nodeunit.Test) {
+    const duration = Duration.days(1);
+
+    test.equal(duration.toSeconds(), 86_400);
+    test.equal(duration.toMinutes(), 1_440);
+    test.equal(duration.toDays(), 1);
+
+    test.done();
+  },
+
+  'toISOString'(test: nodeunit.Test) {
+    test.equal(Duration.seconds(0).toISOString(), 'PT0S');
+    test.equal(Duration.minutes(0).toISOString(), 'PT0S');
+    test.equal(Duration.hours(0).toISOString(), 'PT0S');
+    test.equal(Duration.days(0).toISOString(), 'PT0S');
+
+    test.equal(Duration.seconds(5).toISOString(), 'PT5S');
+    test.equal(Duration.minutes(5).toISOString(), 'PT5M');
+    test.equal(Duration.hours(5).toISOString(), 'PT5H');
+    test.equal(Duration.days(5).toISOString(), 'PT5D');
+
+    test.equal(Duration.seconds(1 + 60 * (1 + 60 * (1 + 24))).toISOString(), 'PT1D1H1M1S');
+
+    test.done();
+  },
+
+  'parse'(test: nodeunit.Test) {
+    test.equal(Duration.parse('PT0S').toSeconds(), 0);
+    test.equal(Duration.parse('PT0M').toSeconds(), 0);
+    test.equal(Duration.parse('PT0H').toSeconds(), 0);
+    test.equal(Duration.parse('PT0D').toSeconds(), 0);
+
+    test.equal(Duration.parse('PT5S').toSeconds(), 5);
+    test.equal(Duration.parse('PT5M').toSeconds(), 300);
+    test.equal(Duration.parse('PT5H').toSeconds(), 18_000);
+    test.equal(Duration.parse('PT5D').toSeconds(), 432_000);
+
+    test.equal(Duration.parse('PT1D1H1M1S').toSeconds(), 1 + 60 * (1 + 60 * (1 + 24)));
+
+    test.done();
+  }
+});
diff --git a/tools/awslint/bin/awslint.ts b/tools/awslint/bin/awslint.ts
index 83d2c5c3e09ac..d34e2d8f3c767 100644
--- a/tools/awslint/bin/awslint.ts
+++ b/tools/awslint/bin/awslint.ts
@@ -5,8 +5,8 @@ import fs = require('fs-extra');
 import reflect = require('jsii-reflect');
 import path = require('path');
 import yargs = require('yargs');
-import { AggregateLinter, apiLinter, attributesLinter, cfnResourceLinter, constructLinter, DiagnosticLevel, eventsLinter, exportsLinter, importsLinter,
-  integrationLinter, moduleLinter, resourceLinter } from '../lib';
+import { AggregateLinter, apiLinter, attributesLinter, cfnResourceLinter, constructLinter, DiagnosticLevel, durationsLinter, eventsLinter, exportsLinter,
+  importsLinter, integrationLinter, moduleLinter, resourceLinter } from '../lib';
 
 const linter = new AggregateLinter(
   moduleLinter,
@@ -18,7 +18,8 @@ const linter = new AggregateLinter(
   attributesLinter,
   exportsLinter,
   eventsLinter,
-  integrationLinter
+  integrationLinter,
+  durationsLinter
 );
 
 let stackTrace = false;
@@ -273,4 +274,4 @@ async function shell(command: string) {
     });
     child.once('error', ko);
   });
-}
\ No newline at end of file
+}
diff --git a/tools/awslint/lib/rules/durations.ts b/tools/awslint/lib/rules/durations.ts
new file mode 100644
index 0000000000000..8a58962ab10e5
--- /dev/null
+++ b/tools/awslint/lib/rules/durations.ts
@@ -0,0 +1,51 @@
+import { Property } from 'jsii-reflect';
+import { Linter } from '../linter';
+
+const DURATION_FQN = '@aws-cdk/cdk.Duration';
+const DURATION_SUFFIX = /(Days|Milli(?:(?:S|s)econd)?s?|Sec(?:ond)?s?)$/;
+
+export const durationsLinter = new Linter(assm => {
+  const result = new Array<Property>();
+  const generatedClassesPrefix = `${assm.name}.Cfn`;
+  for (const type of assm.types) {
+    // L1 classes are exempted from this rule, doing basic name matching here...
+    if (type.fqn.startsWith(generatedClassesPrefix)) { continue; }
+    if (!type.isClassType() && !type.isDataType() && !type.isInterfaceType()) { continue; }
+    for (const property of type.allProperties) {
+      if (isDurationProperty(property)) {
+        result.push(property);
+      }
+    }
+  }
+  return result;
+
+  function isDurationProperty(prop: Property): boolean {
+    const lowerCaseName = prop.name.toLowerCase();
+    // No lookbehind in JS regexes, so excluding "*PerSecond" by hand here...
+    return (DURATION_SUFFIX.test(prop.name) && !/PerSecond$/.test(prop.name))
+      || lowerCaseName.endsWith('duration')
+      || lowerCaseName.endsWith('period')
+      || lowerCaseName.endsWith('timeout')
+      || lowerCaseName.endsWith('ttl')
+      || prop.type.fqn === DURATION_FQN;
+  }
+});
+
+durationsLinter.add({
+  code: 'duration-prop-type',
+  message: `property must be typed ${DURATION_FQN}`,
+  eval: evaluation => {
+    evaluation.assert(evaluation.ctx.type.fqn === DURATION_FQN,
+      `${evaluation.ctx.parentType.fqn}.${evaluation.ctx.name}`);
+  },
+});
+
+durationsLinter.add({
+  code: 'duration-prop-name',
+  message: 'property must not use time-unit suffix',
+  eval: evaluation => {
+    evaluation.assert(!DURATION_SUFFIX.test(evaluation.ctx.name),
+      `${evaluation.ctx.parentType.fqn}.${evaluation.ctx.name}`,
+      `(suggested name: "${evaluation.ctx.name.replace(DURATION_SUFFIX, '')}")`);
+  },
+});
diff --git a/tools/awslint/lib/rules/index.ts b/tools/awslint/lib/rules/index.ts
index 04dffc0af190b..b5fd25c16295a 100644
--- a/tools/awslint/lib/rules/index.ts
+++ b/tools/awslint/lib/rules/index.ts
@@ -1,10 +1,11 @@
-export * from './construct';
-export * from './module';
-export * from './resource';
-export * from './imports';
-export * from './cfn-resource';
-export * from './attributes';
 export * from './api';
-export * from './exports';
+export * from './attributes';
+export * from './cfn-resource';
 export * from './cloudwatch-events';
+export * from './construct';
+export * from './durations';
+export * from './exports';
+export * from './imports';
 export * from './integrations';
+export * from './module';
+export * from './resource';

From 5f9ca7a9783f8944596e0bbcba6d617ec626ed7c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=F0=9F=91=A8=F0=9F=8F=BC=E2=80=8D=F0=9F=92=BB=20Romain=20M?=
 =?UTF-8?q?arcadier-Muller?= <rmuller@amazon.com>
Date: Tue, 18 Jun 2019 10:11:38 +0200
Subject: [PATCH 2/5] Stop the switch madness!

---
 packages/@aws-cdk/cdk/lib/duration.ts       | 95 +++++++--------------
 packages/@aws-cdk/cdk/test/test.duration.ts | 20 +++--
 2 files changed, 47 insertions(+), 68 deletions(-)

diff --git a/packages/@aws-cdk/cdk/lib/duration.ts b/packages/@aws-cdk/cdk/lib/duration.ts
index d8d8ca7f23a3e..083d7a7627817 100644
--- a/packages/@aws-cdk/cdk/lib/duration.ts
+++ b/packages/@aws-cdk/cdk/lib/duration.ts
@@ -75,52 +75,22 @@ export class Duration {
   /**
    * @returns the value of this `Duration` expressed in Seconds.
    */
-  public toSeconds(_opts: TimeConversionOptions = {}): number {
-    switch (this.unit) {
-      case TimeUnit.Seconds:
-        return this.amount;
-      case TimeUnit.Minutes:
-        return this.amount * 60;
-      case TimeUnit.Hours:
-        return this.amount * 3600;
-      case TimeUnit.Days:
-        return this.amount * 86_400;
-      default:
-        throw new Error(`Unexpected time unit: ${this.unit}`);
-    }
+  public toSeconds(opts: TimeConversionOptions = {}): number {
+    return _ensureIntegral(this.amount * this.unit.inSeconds, opts);
   }
 
+  /**
+   * @returns the value of this `Duration` expressed in Minutes.
+   */
   public toMinutes(opts: TimeConversionOptions = {}): number {
-    switch (this.unit) {
-      case TimeUnit.Seconds:
-        return this.safeConversion(60, opts, TimeUnit.Seconds);
-      case TimeUnit.Minutes:
-        return this.amount;
-      case TimeUnit.Hours:
-        return this.amount * 60;
-      case TimeUnit.Days:
-        return this.amount * 1_440;
-      default:
-        throw new Error(`Unexpected time unit: ${this.unit}`);
-    }
+    return _ensureIntegral(this.amount * this.unit.inMinutes, opts);
   }
 
   /**
    * @returns the value of this `Duration` expressed in Days.
    */
   public toDays(opts: TimeConversionOptions = {}): number {
-    switch (this.unit) {
-      case TimeUnit.Seconds:
-        return this.safeConversion(86_400, opts, TimeUnit.Days);
-      case TimeUnit.Minutes:
-        return this.safeConversion(1_440, opts, TimeUnit.Days);
-      case TimeUnit.Hours:
-        return this.safeConversion(24, opts, TimeUnit.Days);
-      case TimeUnit.Days:
-        return this.amount;
-      default:
-        throw new Error(`Unexpected time unit: ${this.unit}`);
-    }
+    return _ensureIntegral(this.amount * this.unit.inDays, opts);
   }
 
   /**
@@ -146,24 +116,6 @@ export class Duration {
     return `${this.amount} ${this.unit}`;
   }
 
-  /**
-   * Divides the current duration by a certain amount and throws an exception if `opts` requires `integral` conversion
-   * and the requirement is not satisfied.
-   *
-   * @param divisor    the value to divide `this.amount` by.
-   * @param opts       conversion options instructing whether integral conversion is required or not.
-   * @param targetUnit the unit of time we are converting to, so it can be used in the error message when needed
-   *
-   * @returns the result of `this.amount / divisor`.
-   */
-  private safeConversion(divisor: number, { integral = true }: TimeConversionOptions, targetUnit: TimeUnit): number {
-    const remainder = this.amount % divisor;
-    if (integral && remainder !== 0) {
-      throw new Error(`Impossible intergal conversion of ${this} to ${targetUnit} was requested`);
-    }
-    return this.amount / divisor;
-  }
-
   private fractionDuration(symbol: string, modulus: number, next: (amount: number) => Duration): string {
     if (this.amount < modulus) {
       return `${this.amount}${symbol}`;
@@ -189,13 +141,6 @@ export interface TimeConversionOptions {
   readonly integral?: boolean;
 }
 
-const enum TimeUnit {
-  Seconds = 's',
-  Minutes = 'minutes',
-  Hours = 'hours',
-  Days = 'days'
-}
-
 /**
  * Helpful syntax sugar for turning an optional `Duration` into a count of seconds.
  *
@@ -206,3 +151,29 @@ const enum TimeUnit {
 export function toSeconds(duration: Duration | undefined): number | undefined {
   return duration && duration.toSeconds();
 }
+
+class TimeUnit {
+  public static readonly Seconds = new TimeUnit('seconds', 1);
+  public static readonly Minutes = new TimeUnit('minutes', 60);
+  public static readonly Hours = new TimeUnit('hours', 3_600);
+  public static readonly Days = new TimeUnit('days', 86_400);
+
+  public readonly inMinutes: number;
+  public readonly inDays: number;
+
+  private constructor(public readonly label: string, public readonly inSeconds: number) {
+    this.inMinutes = inSeconds / 60;
+    this.inDays = inSeconds / 86_400;
+  }
+
+  public toString() {
+    return this.label;
+  }
+}
+
+function _ensureIntegral(value: number, { integral = true }: TimeConversionOptions) {
+  if (!Number.isInteger(value) && integral) {
+    throw new Error(`Required integral time unit conversion, but value ${value} is not integral.`);
+  }
+  return value;
+}
diff --git a/packages/@aws-cdk/cdk/test/test.duration.ts b/packages/@aws-cdk/cdk/test/test.duration.ts
index 7996d7fc86e73..8aeed3b83d1e0 100644
--- a/packages/@aws-cdk/cdk/test/test.duration.ts
+++ b/packages/@aws-cdk/cdk/test/test.duration.ts
@@ -13,8 +13,8 @@ export = nodeunit.testCase({
 
     test.equal(duration.toSeconds(), 300);
     test.equal(duration.toMinutes(), 5);
-    test.throws(() => duration.toDays(), /Impossible intergal conversion of/);
-    test.equal(duration.toDays({ integral: false }), 300 / 86_400);
+    test.throws(() => duration.toDays(), /Required integral time unit conversion, but value/);
+    floatEqual(test, duration.toDays({ integral: false }), 300 / 86_400);
 
     test.equal(Duration.seconds(60 * 60 * 24).toDays(), 1);
 
@@ -26,8 +26,8 @@ export = nodeunit.testCase({
 
     test.equal(duration.toSeconds(), 300);
     test.equal(duration.toMinutes(), 5);
-    test.throws(() => duration.toDays(), /Impossible intergal conversion of/);
-    test.equal(duration.toDays({ integral: false }), 300 / 86_400);
+    test.throws(() => duration.toDays(), /Required integral time unit conversion, but value/);
+    floatEqual(test, duration.toDays({ integral: false }), 300 / 86_400);
 
     test.equal(Duration.minutes(60 * 24).toDays(), 1);
 
@@ -39,8 +39,8 @@ export = nodeunit.testCase({
 
     test.equal(duration.toSeconds(), 18_000);
     test.equal(duration.toMinutes(), 300);
-    test.throws(() => duration.toDays(), /Impossible intergal conversion of/);
-    test.equals(duration.toDays({ integral: false }), 5 / 24);
+    test.throws(() => duration.toDays(), /Required integral time unit conversion, but value/);
+    floatEqual(test, duration.toDays({ integral: false }), 5 / 24);
 
     test.equal(Duration.hours(24).toDays(), 1);
 
@@ -89,3 +89,11 @@ export = nodeunit.testCase({
     test.done();
   }
 });
+
+function floatEqual(test: nodeunit.Test, actual: number, expected: number) {
+  test.ok(
+    // Floats are subject to rounding errors up to Number.ESPILON
+    actual >= expected - Number.EPSILON && actual <= expected + Number.EPSILON,
+    `${actual} == ${expected}`,
+  );
+}

From d1ef198769875e00271c42752a2502b0cb9528e8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=F0=9F=91=A8=F0=9F=8F=BC=E2=80=8D=F0=9F=92=BB=20Romain=20M?=
 =?UTF-8?q?arcadier-Muller?= <rmuller@amazon.com>
Date: Thu, 20 Jun 2019 12:19:57 +0200
Subject: [PATCH 3/5] PR Feedback

1. Dropped the free-floating toSeconds function
2. Added test for unresolved tokens in constructor
3. Made .toString() return a breaking token.
---
 packages/@aws-cdk/aws-apigateway/lib/stage.ts |  2 +-
 .../lib/step-scaling-action.ts                |  2 +-
 .../lib/target-tracking-scaling-policy.ts     |  4 ++--
 .../aws-autoscaling/lib/lifecycle-hook.ts     |  2 +-
 .../lib/step-scaling-action.ts                |  2 +-
 .../lib/target-tracking-scaling-policy.ts     |  2 +-
 .../aws-cloudfront/lib/web_distribution.ts    | 10 ++++----
 .../@aws-cdk/aws-ecs/lib/base/base-service.ts |  2 +-
 .../aws-ecs/lib/container-definition.ts       |  2 +-
 packages/@aws-cdk/aws-iam/lib/role.ts         |  2 +-
 packages/@aws-cdk/aws-lambda/lib/function.ts  |  2 +-
 packages/@aws-cdk/aws-rds/lib/instance.ts     |  2 +-
 packages/@aws-cdk/aws-sqs/lib/queue.ts        |  8 +++----
 .../@aws-cdk/aws-sqs/lib/validate-props.ts    |  8 +++----
 .../lib/send-to-queue.ts                      |  2 +-
 .../aws-stepfunctions/lib/states/state.ts     |  2 +-
 .../aws-stepfunctions/lib/states/task.ts      |  4 ++--
 packages/@aws-cdk/cdk/lib/duration.ts         | 23 +++++++++----------
 packages/@aws-cdk/cdk/test/test.duration.ts   |  8 ++++++-
 19 files changed, 47 insertions(+), 42 deletions(-)

diff --git a/packages/@aws-cdk/aws-apigateway/lib/stage.ts b/packages/@aws-cdk/aws-apigateway/lib/stage.ts
index 6e4000ca756ba..a633c6f5af50a 100644
--- a/packages/@aws-cdk/aws-apigateway/lib/stage.ts
+++ b/packages/@aws-cdk/aws-apigateway/lib/stage.ts
@@ -256,7 +256,7 @@ export class Stage extends Resource {
       return {
         httpMethod, resourcePath,
         cacheDataEncrypted: options.cacheDataEncrypted,
-        cacheTtlInSeconds: toSeconds(options.cacheTtl),
+        cacheTtlInSeconds: options.cacheTtl && options.cacheTtl.toSeconds(),
         cachingEnabled: options.cachingEnabled,
         dataTraceEnabled: options.dataTraceEnabled,
         loggingLevel: options.loggingLevel,
diff --git a/packages/@aws-cdk/aws-applicationautoscaling/lib/step-scaling-action.ts b/packages/@aws-cdk/aws-applicationautoscaling/lib/step-scaling-action.ts
index bb9fe106377c8..9018bff1f665f 100644
--- a/packages/@aws-cdk/aws-applicationautoscaling/lib/step-scaling-action.ts
+++ b/packages/@aws-cdk/aws-applicationautoscaling/lib/step-scaling-action.ts
@@ -86,7 +86,7 @@ export class StepScalingAction extends cdk.Construct {
       scalingTargetId: props.scalingTarget.scalableTargetId,
       stepScalingPolicyConfiguration: {
         adjustmentType: props.adjustmentType,
-        cooldown: cdk.toSeconds(props.cooldown),
+        cooldown: props.cooldown && props.cooldown.toSeconds(),
         minAdjustmentMagnitude: props.minAdjustmentMagnitude,
         metricAggregationType: props.metricAggregationType,
         stepAdjustments: cdk.Lazy.anyValue({ produce: () => this.adjustments }),
diff --git a/packages/@aws-cdk/aws-applicationautoscaling/lib/target-tracking-scaling-policy.ts b/packages/@aws-cdk/aws-applicationautoscaling/lib/target-tracking-scaling-policy.ts
index 4c653c5a721e8..316ac0479c0b2 100644
--- a/packages/@aws-cdk/aws-applicationautoscaling/lib/target-tracking-scaling-policy.ts
+++ b/packages/@aws-cdk/aws-applicationautoscaling/lib/target-tracking-scaling-policy.ts
@@ -128,8 +128,8 @@ export class TargetTrackingScalingPolicy extends cdk.Construct {
           predefinedMetricType: props.predefinedMetric,
           resourceLabel: props.resourceLabel,
         } : undefined,
-        scaleInCooldown: cdk.toSeconds(props.scaleInCooldown),
-        scaleOutCooldown: cdk.toSeconds(props.scaleOutCooldown),
+        scaleInCooldown: props.scaleInCooldown && props.scaleInCooldown.toSeconds(),
+        scaleOutCooldown: props.scaleOutCooldown && props.scaleOutCooldown.toSeconds(),
         targetValue: props.targetValue
       }
     });
diff --git a/packages/@aws-cdk/aws-autoscaling/lib/lifecycle-hook.ts b/packages/@aws-cdk/aws-autoscaling/lib/lifecycle-hook.ts
index 4292008bc49c0..daea56c782044 100644
--- a/packages/@aws-cdk/aws-autoscaling/lib/lifecycle-hook.ts
+++ b/packages/@aws-cdk/aws-autoscaling/lib/lifecycle-hook.ts
@@ -103,7 +103,7 @@ export class LifecycleHook extends Resource implements ILifecycleHook {
     const resource = new CfnLifecycleHook(this, 'Resource', {
       autoScalingGroupName: props.autoScalingGroup.autoScalingGroupName,
       defaultResult: props.defaultResult,
-      heartbeatTimeout: toSeconds(props.heartbeatTimeout),
+      heartbeatTimeout: props.heartbeatTimeout && props.heartbeatTimeout.toSeconds(),
       lifecycleHookName: props.lifecycleHookName,
       lifecycleTransition: props.lifecycleTransition,
       notificationMetadata: props.notificationMetadata,
diff --git a/packages/@aws-cdk/aws-autoscaling/lib/step-scaling-action.ts b/packages/@aws-cdk/aws-autoscaling/lib/step-scaling-action.ts
index 892010ec9d247..f55430c5e2668 100644
--- a/packages/@aws-cdk/aws-autoscaling/lib/step-scaling-action.ts
+++ b/packages/@aws-cdk/aws-autoscaling/lib/step-scaling-action.ts
@@ -74,7 +74,7 @@ export class StepScalingAction extends cdk.Construct {
       policyType: 'StepScaling',
       autoScalingGroupName: props.autoScalingGroup.autoScalingGroupName,
       cooldown: props.cooldown && props.cooldown.toSeconds().toString(),
-      estimatedInstanceWarmup: cdk.toSeconds(props.estimatedInstanceWarmup),
+      estimatedInstanceWarmup: props.estimatedInstanceWarmup && props.estimatedInstanceWarmup.toSeconds(),
       adjustmentType: props.adjustmentType,
       minAdjustmentMagnitude: props.minAdjustmentMagnitude,
       metricAggregationType: props.metricAggregationType,
diff --git a/packages/@aws-cdk/aws-autoscaling/lib/target-tracking-scaling-policy.ts b/packages/@aws-cdk/aws-autoscaling/lib/target-tracking-scaling-policy.ts
index 29c65923dace5..d3fdfb5712abb 100644
--- a/packages/@aws-cdk/aws-autoscaling/lib/target-tracking-scaling-policy.ts
+++ b/packages/@aws-cdk/aws-autoscaling/lib/target-tracking-scaling-policy.ts
@@ -123,7 +123,7 @@ export class TargetTrackingScalingPolicy extends cdk.Construct {
       policyType: 'TargetTrackingScaling',
       autoScalingGroupName: props.autoScalingGroup.autoScalingGroupName,
       cooldown: props.cooldown && props.cooldown.toSeconds().toString(),
-      estimatedInstanceWarmup: cdk.toSeconds(props.estimatedInstanceWarmup),
+      estimatedInstanceWarmup: props.estimatedInstanceWarmup && props.estimatedInstanceWarmup.toSeconds(),
       targetTrackingConfiguration: {
         customizedMetricSpecification: renderCustomMetric(props.customMetric),
         disableScaleIn: props.disableScaleIn,
diff --git a/packages/@aws-cdk/aws-cloudfront/lib/web_distribution.ts b/packages/@aws-cdk/aws-cloudfront/lib/web_distribution.ts
index f60ed7a968ff6..fa05d34e803ec 100644
--- a/packages/@aws-cdk/aws-cloudfront/lib/web_distribution.ts
+++ b/packages/@aws-cdk/aws-cloudfront/lib/web_distribution.ts
@@ -606,8 +606,8 @@ export class CloudFrontWebDistribution extends cdk.Construct implements IDistrib
           ? {
             httpPort: originConfig.customOriginSource.httpPort || 80,
             httpsPort: originConfig.customOriginSource.httpsPort || 443,
-            originKeepaliveTimeout: cdk.toSeconds(originConfig.customOriginSource.originKeepaliveTimeout) || 5,
-            originReadTimeout: cdk.toSeconds(originConfig.customOriginSource.originReadTimeout) || 30,
+            originKeepaliveTimeout: originConfig.customOriginSource.originKeepaliveTimeout && originConfig.customOriginSource.originKeepaliveTimeout.toSeconds() || 5,
+            originReadTimeout: originConfig.customOriginSource.originReadTimeout && originConfig.customOriginSource.originReadTimeout.toSeconds() || 30,
             originProtocolPolicy: originConfig.customOriginSource.originProtocolPolicy || OriginProtocolPolicy.HttpsOnly,
             originSslProtocols: originConfig.customOriginSource.allowedOriginSSLVersions || [OriginSslPolicy.TLSv1_2]
           }
@@ -704,10 +704,10 @@ export class CloudFrontWebDistribution extends cdk.Construct implements IDistrib
       allowedMethods: this.METHOD_LOOKUP_MAP[input.allowedMethods || CloudFrontAllowedMethods.GET_HEAD],
       cachedMethods: this.METHOD_LOOKUP_MAP[input.cachedMethods || CloudFrontAllowedCachedMethods.GET_HEAD],
       compress: input.compress,
-      defaultTtl: cdk.toSeconds(input.defaultTtl),
+      defaultTtl: input.defaultTtl && input.defaultTtl.toSeconds(),
       forwardedValues: input.forwardedValues || { queryString: false, cookies: { forward: "none" } },
-      maxTtl: cdk.toSeconds(input.maxTtl),
-      minTtl: cdk.toSeconds(input.minTtl),
+      maxTtl: input.maxTtl && input.maxTtl.toSeconds(),
+      minTtl: input.minTtl && input.minTtl.toSeconds(),
       trustedSigners: input.trustedSigners,
       targetOriginId: input.targetOriginId,
       viewerProtocolPolicy: protoPolicy || ViewerProtocolPolicy.RedirectToHTTPS,
diff --git a/packages/@aws-cdk/aws-ecs/lib/base/base-service.ts b/packages/@aws-cdk/aws-ecs/lib/base/base-service.ts
index 423f048993954..ca82535c66ccd 100644
--- a/packages/@aws-cdk/aws-ecs/lib/base/base-service.ts
+++ b/packages/@aws-cdk/aws-ecs/lib/base/base-service.ts
@@ -150,7 +150,7 @@ export abstract class BaseService extends Resource
         maximumPercent: props.maximumPercent || 200,
         minimumHealthyPercent: props.minimumHealthyPercent === undefined ? 50 : props.minimumHealthyPercent
       },
-      healthCheckGracePeriodSeconds: toSeconds(props.healthCheckGracePeriod),
+      healthCheckGracePeriodSeconds: props.healthCheckGracePeriod && props.healthCheckGracePeriod.toSeconds(),
       /* role: never specified, supplanted by Service Linked Role */
       networkConfiguration: Lazy.anyValue({ produce: () => this.networkConfiguration }),
       serviceRegistries: Lazy.anyValue({ produce: () => this.serviceRegistries }),
diff --git a/packages/@aws-cdk/aws-ecs/lib/container-definition.ts b/packages/@aws-cdk/aws-ecs/lib/container-definition.ts
index daca16ee46e25..61d284f32d558 100644
--- a/packages/@aws-cdk/aws-ecs/lib/container-definition.ts
+++ b/packages/@aws-cdk/aws-ecs/lib/container-definition.ts
@@ -479,7 +479,7 @@ function renderHealthCheck(hc: HealthCheck): CfnTaskDefinition.HealthCheckProper
     command: getHealthCheckCommand(hc),
     interval: hc.interval != null ? hc.interval.toSeconds() : 30,
     retries: hc.retries !== undefined ? hc.retries : 3,
-    startPeriod: cdk.toSeconds(hc.startPeriod),
+    startPeriod: hc.startPeriod && hc.startPeriod.toSeconds(),
     timeout: hc.timeout !== undefined ? hc.timeout.toSeconds() : 5,
   };
 }
diff --git a/packages/@aws-cdk/aws-iam/lib/role.ts b/packages/@aws-cdk/aws-iam/lib/role.ts
index 53b19ac53fd8a..04d5403fcfe0e 100644
--- a/packages/@aws-cdk/aws-iam/lib/role.ts
+++ b/packages/@aws-cdk/aws-iam/lib/role.ts
@@ -196,7 +196,7 @@ export class Role extends Resource implements IRole {
     this.assumeRolePolicy = createAssumeRolePolicy(props.assumedBy, props.externalId);
     this.managedPolicyArns = props.managedPolicyArns || [ ];
 
-    const maxSessionDuration = toSeconds(props.maxSessionDuration);
+    const maxSessionDuration = props.maxSessionDuration && props.maxSessionDuration.toSeconds();
     validateMaxSessionDuration(maxSessionDuration);
 
     const role = new CfnRole(this, 'Resource', {
diff --git a/packages/@aws-cdk/aws-lambda/lib/function.ts b/packages/@aws-cdk/aws-lambda/lib/function.ts
index 806445b27dc47..22db76797d5f2 100644
--- a/packages/@aws-cdk/aws-lambda/lib/function.ts
+++ b/packages/@aws-cdk/aws-lambda/lib/function.ts
@@ -427,7 +427,7 @@ export class Function extends FunctionBase {
       code: Lazy.anyValue({ produce: () => props.code._toJSON(resource) }),
       layers: Lazy.listValue({ produce: () => this.layers.map(layer => layer.layerVersionArn) }, { omitEmpty: true }),
       handler: props.handler,
-      timeout: toSeconds(props.timeout),
+      timeout: props.timeout && props.timeout.toSeconds(),
       runtime: props.runtime.name,
       role: this.role.roleArn,
       environment: Lazy.anyValue({ produce: () => this.renderEnvironment() }),
diff --git a/packages/@aws-cdk/aws-rds/lib/instance.ts b/packages/@aws-cdk/aws-rds/lib/instance.ts
index 4a3c063ee0b45..0e832f40fee56 100644
--- a/packages/@aws-cdk/aws-rds/lib/instance.ts
+++ b/packages/@aws-cdk/aws-rds/lib/instance.ts
@@ -518,7 +518,7 @@ abstract class DatabaseInstanceNew extends DatabaseInstanceBase implements IData
       enableIamDatabaseAuthentication: props.iamAuthentication,
       enablePerformanceInsights: props.enablePerformanceInsights,
       iops,
-      monitoringInterval: toSeconds(props.monitoringInterval),
+      monitoringInterval: props.monitoringInterval && props.monitoringInterval.toSeconds(),
       monitoringRoleArn: monitoringRole && monitoringRole.roleArn,
       multiAz: props.multiAz,
       optionGroupName: props.optionGroup && props.optionGroup.optionGroupName,
diff --git a/packages/@aws-cdk/aws-sqs/lib/queue.ts b/packages/@aws-cdk/aws-sqs/lib/queue.ts
index 485eb1d5b15c5..ff29b57729fc0 100644
--- a/packages/@aws-cdk/aws-sqs/lib/queue.ts
+++ b/packages/@aws-cdk/aws-sqs/lib/queue.ts
@@ -248,11 +248,11 @@ export class Queue extends QueueBase {
       ...this.determineFifoProps(props),
       ...encryptionProps,
       redrivePolicy,
-      delaySeconds: toSeconds(props.deliveryDelay),
+      delaySeconds: props.deliveryDelay && props.deliveryDelay.toSeconds(),
       maximumMessageSize: props.maxMessageSizeBytes,
-      messageRetentionPeriod: toSeconds(props.retentionPeriod),
-      receiveMessageWaitTimeSeconds: toSeconds(props.receiveMessageWaitTime),
-      visibilityTimeout: toSeconds(props.visibilityTimeout),
+      messageRetentionPeriod: props.retentionPeriod && props.retentionPeriod.toSeconds(),
+      receiveMessageWaitTimeSeconds: props.receiveMessageWaitTime && props.receiveMessageWaitTime.toSeconds(),
+      visibilityTimeout: props.visibilityTimeout && props.visibilityTimeout.toSeconds(),
     });
     this.encryptionMasterKey = encryptionMasterKey;
     this.queueArn = queue.queueArn;
diff --git a/packages/@aws-cdk/aws-sqs/lib/validate-props.ts b/packages/@aws-cdk/aws-sqs/lib/validate-props.ts
index 45bf28894e084..5dafcdfe5a94e 100644
--- a/packages/@aws-cdk/aws-sqs/lib/validate-props.ts
+++ b/packages/@aws-cdk/aws-sqs/lib/validate-props.ts
@@ -2,11 +2,11 @@ import { toSeconds } from '@aws-cdk/cdk';
 import { QueueProps } from './index';
 
 export function validateProps(props: QueueProps) {
-  validateRange('delivery delay', toSeconds(props.deliveryDelay), 0, 900, 'seconds');
+  validateRange('delivery delay', props.deliveryDelay && props.deliveryDelay.toSeconds(), 0, 900, 'seconds');
   validateRange('maximum message size', props.maxMessageSizeBytes, 1_024, 262_144, 'bytes');
-  validateRange('message retention period', toSeconds(props.retentionPeriod), 60, 1_209_600, 'seconds');
-  validateRange('receive wait time', toSeconds(props.receiveMessageWaitTime), 0, 20, 'seconds');
-  validateRange('visibility timeout', toSeconds(props.visibilityTimeout), 0, 43_200, 'seconds');
+  validateRange('message retention period', props.retentionPeriod && props.retentionPeriod.toSeconds(), 60, 1_209_600, 'seconds');
+  validateRange('receive wait time', props.receiveMessageWaitTime && props.receiveMessageWaitTime.toSeconds(), 0, 20, 'seconds');
+  validateRange('visibility timeout', props.visibilityTimeout && props.visibilityTimeout.toSeconds(), 0, 43_200, 'seconds');
   validateRange('dead letter target maximum receive count', props.deadLetterQueue && props.deadLetterQueue.maxReceiveCount, 1, +Infinity);
 }
 
diff --git a/packages/@aws-cdk/aws-stepfunctions-tasks/lib/send-to-queue.ts b/packages/@aws-cdk/aws-stepfunctions-tasks/lib/send-to-queue.ts
index 87c3075371a10..c63a45823c77f 100644
--- a/packages/@aws-cdk/aws-stepfunctions-tasks/lib/send-to-queue.ts
+++ b/packages/@aws-cdk/aws-stepfunctions-tasks/lib/send-to-queue.ts
@@ -60,7 +60,7 @@ export class SendToQueue implements sfn.IStepFunctionsTask {
         QueueUrl: this.queue.queueUrl,
         ...sfn.FieldUtils.renderObject({
           MessageBody: this.props.messageBody.value,
-          DelaySeconds: toSeconds(this.props.delay),
+          DelaySeconds: this.props.delay && this.props.delay.toSeconds(),
           MessageDeduplicationId: this.props.messageDeduplicationId,
           MessageGroupId: this.props.messageGroupId,
         })
diff --git a/packages/@aws-cdk/aws-stepfunctions/lib/states/state.ts b/packages/@aws-cdk/aws-stepfunctions/lib/states/state.ts
index 2b333b91e3e43..edbabaddb9712 100644
--- a/packages/@aws-cdk/aws-stepfunctions/lib/states/state.ts
+++ b/packages/@aws-cdk/aws-stepfunctions/lib/states/state.ts
@@ -437,7 +437,7 @@ interface CatchTransition {
 function renderRetry(retry: RetryProps) {
     return {
         ErrorEquals: retry.errors,
-        IntervalSeconds: cdk.toSeconds(retry.interval),
+        IntervalSeconds: retry.interval && retry.interval.toSeconds(),
         MaxAttempts: retry.maxAttempts,
         BackoffRate: retry.backoffRate
     };
diff --git a/packages/@aws-cdk/aws-stepfunctions/lib/states/task.ts b/packages/@aws-cdk/aws-stepfunctions/lib/states/task.ts
index 10b41d3c7f37b..5e82f737d8218 100644
--- a/packages/@aws-cdk/aws-stepfunctions/lib/states/task.ts
+++ b/packages/@aws-cdk/aws-stepfunctions/lib/states/task.ts
@@ -128,8 +128,8 @@ export class Task extends State implements INextable {
             Resource: this.taskProps.resourceArn,
             Parameters: this.taskProps.parameters,
             ResultPath: renderJsonPath(this.resultPath),
-            TimeoutSeconds: cdk.toSeconds(this.timeout),
-            HeartbeatSeconds: cdk.toSeconds(this.taskProps.heartbeat),
+            TimeoutSeconds: this.timeout && this.timeout.toSeconds(),
+            HeartbeatSeconds: this.taskProps.heartbeat && this.taskProps.heartbeat.toSeconds(),
         };
     }
 
diff --git a/packages/@aws-cdk/cdk/lib/duration.ts b/packages/@aws-cdk/cdk/lib/duration.ts
index 083d7a7627817..5802f899bf412 100644
--- a/packages/@aws-cdk/cdk/lib/duration.ts
+++ b/packages/@aws-cdk/cdk/lib/duration.ts
@@ -1,3 +1,5 @@
+import { Token } from "./token";
+
 /**
  * Represents a length of time.
  */
@@ -64,6 +66,9 @@ export class Duration {
   private readonly unit: TimeUnit;
 
   private constructor(amount: number, unit: TimeUnit) {
+    if (Token.isUnresolved(amount)) {
+      throw new Error(`Duration amounts cannot be unresolved tokens. Received ${amount}`);
+    }
     if (amount < 0) {
       throw new Error(`Duration amounts cannot be negative. Received: ${amount}`);
     }
@@ -113,7 +118,12 @@ export class Duration {
   }
 
   public toString(): string {
-    return `${this.amount} ${this.unit}`;
+    return Token.asString(
+      () => {
+        throw new Error(`Duration.toString() was used, but .toSeconds, .toMinutes or .toDays should have been called instead`);
+      },
+      { displayHint: `${this.amount} ${this.unit.label}` }
+    );
   }
 
   private fractionDuration(symbol: string, modulus: number, next: (amount: number) => Duration): string {
@@ -141,17 +151,6 @@ export interface TimeConversionOptions {
   readonly integral?: boolean;
 }
 
-/**
- * Helpful syntax sugar for turning an optional `Duration` into a count of seconds.
- *
- * @param duration an optional duration to convert into an amount of sunctions.
- *
- * @return `duration && duration.toSeconds()`.
- */
-export function toSeconds(duration: Duration | undefined): number | undefined {
-  return duration && duration.toSeconds();
-}
-
 class TimeUnit {
   public static readonly Seconds = new TimeUnit('seconds', 1);
   public static readonly Minutes = new TimeUnit('minutes', 60);
diff --git a/packages/@aws-cdk/cdk/test/test.duration.ts b/packages/@aws-cdk/cdk/test/test.duration.ts
index 8aeed3b83d1e0..817beae932cf2 100644
--- a/packages/@aws-cdk/cdk/test/test.duration.ts
+++ b/packages/@aws-cdk/cdk/test/test.duration.ts
@@ -1,5 +1,5 @@
 import nodeunit = require('nodeunit');
-import { Duration } from '../lib';
+import { Duration, Stack, Token } from '../lib';
 
 export = nodeunit.testCase({
   'negative amount'(test: nodeunit.Test) {
@@ -8,6 +8,12 @@ export = nodeunit.testCase({
     test.done();
   },
 
+  'unresolved amount'(test: nodeunit.Test) {
+    test.throws(new Stack().resolve(Duration.seconds(Token.asNumber(1337))));
+
+    test.done();
+  },
+
   'Duration in seconds'(test: nodeunit.Test) {
     const duration = Duration.seconds(300);
 

From f6d890a10faebc90f25a01bde9826d8c662752d8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=F0=9F=91=A8=F0=9F=8F=BC=E2=80=8D=F0=9F=92=BB=20Romain=20M?=
 =?UTF-8?q?arcadier-Muller?= <rmuller@amazon.com>
Date: Thu, 20 Jun 2019 14:36:51 +0200
Subject: [PATCH 4/5] Last feedback

---
 packages/@aws-cdk/cdk/lib/cfn-resource.ts    |  5 +--
 packages/@aws-cdk/cdk/lib/duration.ts        | 40 ++++++++++++++------
 packages/@aws-cdk/cdk/lib/resource-policy.ts |  4 +-
 packages/@aws-cdk/cdk/package.json           |  3 +-
 packages/@aws-cdk/cdk/test/test.duration.ts  |  7 +++-
 5 files changed, 37 insertions(+), 22 deletions(-)

diff --git a/packages/@aws-cdk/cdk/lib/cfn-resource.ts b/packages/@aws-cdk/cdk/lib/cfn-resource.ts
index b343fbf402b6e..2f0fb721c8ba6 100644
--- a/packages/@aws-cdk/cdk/lib/cfn-resource.ts
+++ b/packages/@aws-cdk/cdk/lib/cfn-resource.ts
@@ -272,10 +272,7 @@ export class CfnResource extends CfnRefElement {
       if (!policy) { return undefined; }
       const result: any = { ...policy };
       if (policy.resourceSignal && policy.resourceSignal.timeout) {
-        result.resourceSignal = {
-          ...policy.resourceSignal,
-          timeout: policy.resourceSignal.timeout.toISOString(),
-        };
+        result.resourceSignal = policy.resourceSignal;
       }
       return result;
     }
diff --git a/packages/@aws-cdk/cdk/lib/duration.ts b/packages/@aws-cdk/cdk/lib/duration.ts
index 5802f899bf412..d9ba10c861373 100644
--- a/packages/@aws-cdk/cdk/lib/duration.ts
+++ b/packages/@aws-cdk/cdk/lib/duration.ts
@@ -2,6 +2,11 @@ import { Token } from "./token";
 
 /**
  * Represents a length of time.
+ *
+ * The amount can be specified either as a literal value (e.g: `10`) which
+ * cannot be negative, or as an unresolved number token.
+ *
+ * Whent he amount is passed as an token, unit conversion is not possible.
  */
 export class Duration {
   /**
@@ -37,6 +42,8 @@ export class Duration {
   }
 
   /**
+   * Parse a period formatted according to the ISO 8601 standard (see https://www.iso.org/fr/standard/70907.html).
+   *
    * @param duration an ISO-formtted duration to be parsed.
    * @returns the parsed `Duration`.
    */
@@ -51,9 +58,9 @@ export class Duration {
     }
     return Duration.seconds(
       _toInt(seconds)
-      + (_toInt(minutes) * 60)
-      + (_toInt(hours) * 3_600)
-      + (_toInt(days) * 86_400)
+      + (_toInt(minutes) * TimeUnit.Minutes.inSeconds)
+      + (_toInt(hours) * TimeUnit.Hours.inSeconds)
+      + (_toInt(days) * TimeUnit.Days.inSeconds)
     );
 
     function _toInt(str: string): number {
@@ -66,10 +73,7 @@ export class Duration {
   private readonly unit: TimeUnit;
 
   private constructor(amount: number, unit: TimeUnit) {
-    if (Token.isUnresolved(amount)) {
-      throw new Error(`Duration amounts cannot be unresolved tokens. Received ${amount}`);
-    }
-    if (amount < 0) {
+    if (!Token.isUnresolved(amount) && amount < 0) {
       throw new Error(`Duration amounts cannot be negative. Received: ${amount}`);
     }
 
@@ -81,25 +85,28 @@ export class Duration {
    * @returns the value of this `Duration` expressed in Seconds.
    */
   public toSeconds(opts: TimeConversionOptions = {}): number {
-    return _ensureIntegral(this.amount * this.unit.inSeconds, opts);
+    if (this.unit === TimeUnit.Seconds) { return this.amount; }
+    return _ensureIntegral(this.amount, this.unit.inSeconds, opts);
   }
 
   /**
    * @returns the value of this `Duration` expressed in Minutes.
    */
   public toMinutes(opts: TimeConversionOptions = {}): number {
-    return _ensureIntegral(this.amount * this.unit.inMinutes, opts);
+    if (this.unit === TimeUnit.Minutes) { return this.amount; }
+    return _ensureIntegral(this.amount, this.unit.inMinutes, opts);
   }
 
   /**
    * @returns the value of this `Duration` expressed in Days.
    */
   public toDays(opts: TimeConversionOptions = {}): number {
-    return _ensureIntegral(this.amount * this.unit.inDays, opts);
+    if (this.unit === TimeUnit.Days) { return this.amount; }
+    return _ensureIntegral(this.amount, this.unit.inDays, opts);
   }
 
   /**
-   * @returns ISO representation of this period.
+   * @returns an ISO 8601 representation of this period (see https://www.iso.org/fr/standard/70907.html).
    */
   public toISOString(): string {
     if (this.amount === 0) { return 'PT0S'; }
@@ -117,6 +124,11 @@ export class Duration {
     }
   }
 
+  /**
+   * Returns a string representation of this `Duration` that is also a Token that cannot be successfully resolved. This
+   * protects users against inadvertently stringifying a `Duration` object, when they should have called one of the
+   * `to*` methods instead.
+   */
   public toString(): string {
     return Token.asString(
       () => {
@@ -170,7 +182,11 @@ class TimeUnit {
   }
 }
 
-function _ensureIntegral(value: number, { integral = true }: TimeConversionOptions) {
+function _ensureIntegral(amount: number, multiplier: number, { integral = true }: TimeConversionOptions): number {
+  if (Token.isUnresolved(amount)) {
+    throw new Error(`Unable to perform time unit conversion on un-resolved token ${amount}.`);
+  }
+  const value = amount * multiplier;
   if (!Number.isInteger(value) && integral) {
     throw new Error(`Required integral time unit conversion, but value ${value} is not integral.`);
   }
diff --git a/packages/@aws-cdk/cdk/lib/resource-policy.ts b/packages/@aws-cdk/cdk/lib/resource-policy.ts
index 20bc69c8f8d42..a3ff6b9d84691 100644
--- a/packages/@aws-cdk/cdk/lib/resource-policy.ts
+++ b/packages/@aws-cdk/cdk/lib/resource-policy.ts
@@ -1,5 +1,3 @@
-import { Duration } from "./duration";
-
 /**
  * Associate the CreationPolicy attribute with a resource to prevent its status from reaching create complete until
  * AWS CloudFormation receives a specified number of success signals or the timeout period is exceeded. To signal a
@@ -63,7 +61,7 @@ export interface ResourceSignal {
    * The timeout period starts after AWS CloudFormation starts creating the resource, and the timeout expires no sooner
    * than the time you specify but can occur shortly thereafter. The maximum time that you can specify is 12 hours.
    */
-  readonly timeout?: Duration;
+  readonly timeout?: string;
 }
 
 /**
diff --git a/packages/@aws-cdk/cdk/package.json b/packages/@aws-cdk/cdk/package.json
index afd66bd76b80b..04b2a465c89ac 100644
--- a/packages/@aws-cdk/cdk/package.json
+++ b/packages/@aws-cdk/cdk/package.json
@@ -36,6 +36,7 @@
       "construct-ctor:@aws-cdk/cdk.App.<initializer>",
       "construct-ctor:@aws-cdk/cdk.Root.<initializer>",
       "construct-ctor:@aws-cdk/cdk.Stack.<initializer>.params*",
+      "duration-prop-type:@aws-cdk/cdk.ResourceSignal.timeout",
       "props-no-any:@aws-cdk/cdk.CfnOutputProps.value",
       "props-no-any:@aws-cdk/cdk.CfnParameterProps.default",
       "props-no-any:@aws-cdk/cdk.CfnResourceProps.properties",
@@ -90,4 +91,4 @@
     "node": ">= 8.10.0"
   },
   "stability": "experimental"
-}
\ No newline at end of file
+}
diff --git a/packages/@aws-cdk/cdk/test/test.duration.ts b/packages/@aws-cdk/cdk/test/test.duration.ts
index b7d438a707b45..a7c2a9c9b630d 100644
--- a/packages/@aws-cdk/cdk/test/test.duration.ts
+++ b/packages/@aws-cdk/cdk/test/test.duration.ts
@@ -9,9 +9,12 @@ export = nodeunit.testCase({
   },
 
   'unresolved amount'(test: nodeunit.Test) {
+    const stack = new Stack();
+    const lazyDuration = Duration.seconds(Token.asNumber({ resolve: () => 1337 }));
+    test.equals(stack.resolve(lazyDuration.toSeconds()), 1337);
     test.throws(
-      () => new Stack().resolve(Duration.seconds(Token.asNumber({ resolve: () => 1337 }))),
-      /Duration amounts cannot be unresolved tokens./
+      () => stack.resolve(lazyDuration.toMinutes()),
+      /Unable to perform time unit conversion on un-resolved token/
     );
 
     test.done();

From 91dc9511054c59c551e2b07e4b39bcf8c7fe4bc9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=F0=9F=91=A8=F0=9F=8F=BC=E2=80=8D=F0=9F=92=BB=20Romain=20M?=
 =?UTF-8?q?arcadier-Muller?= <rmuller@amazon.com>
Date: Thu, 20 Jun 2019 14:38:23 +0200
Subject: [PATCH 5/5] Rename CloudTrail log retention

---
 packages/@aws-cdk/aws-cloudtrail/lib/index.ts            | 4 ++--
 packages/@aws-cdk/aws-cloudtrail/package.json            | 6 ------
 packages/@aws-cdk/aws-cloudtrail/test/test.cloudtrail.ts | 2 +-
 3 files changed, 3 insertions(+), 9 deletions(-)

diff --git a/packages/@aws-cdk/aws-cloudtrail/lib/index.ts b/packages/@aws-cdk/aws-cloudtrail/lib/index.ts
index dc76d342c39a3..b2893e7c7b874 100644
--- a/packages/@aws-cdk/aws-cloudtrail/lib/index.ts
+++ b/packages/@aws-cdk/aws-cloudtrail/lib/index.ts
@@ -67,7 +67,7 @@ export interface TrailProps {
    *
    *  @default logs.RetentionDays.OneYear
    */
-  readonly cloudWatchLogsRetentionTimeDays?: logs.RetentionDays;
+  readonly cloudWatchLogsRetention?: logs.RetentionDays;
 
   /** The AWS Key Management Service (AWS KMS) key ID that you want to use to encrypt CloudTrail logs.
    *
@@ -151,7 +151,7 @@ export class Trail extends Resource {
     let logsRole: iam.IRole | undefined;
     if (props.sendToCloudWatchLogs) {
       logGroup = new logs.CfnLogGroup(this, "LogGroup", {
-        retentionInDays: props.cloudWatchLogsRetentionTimeDays || logs.RetentionDays.ONE_YEAR
+        retentionInDays: props.cloudWatchLogsRetention || logs.RetentionDays.ONE_YEAR
       });
 
       logsRole = new iam.Role(this, 'LogsRole', { assumedBy: cloudTrailPrincipal });
diff --git a/packages/@aws-cdk/aws-cloudtrail/package.json b/packages/@aws-cdk/aws-cloudtrail/package.json
index 2db2b332b0a1a..1003530de1d4a 100644
--- a/packages/@aws-cdk/aws-cloudtrail/package.json
+++ b/packages/@aws-cdk/aws-cloudtrail/package.json
@@ -88,12 +88,6 @@
     "@aws-cdk/aws-s3": "^0.35.0",
     "@aws-cdk/cdk": "^0.35.0"
   },
-  "awslint": {
-    "exclude": [
-      "duration-prop-type:@aws-cdk/aws-cloudtrail.TrailProps.cloudWatchLogsRetentionTimeDays",
-      "duration-prop-name:@aws-cdk/aws-cloudtrail.TrailProps.cloudWatchLogsRetentionTimeDays"
-    ]
-  },
   "engines": {
     "node": ">= 8.10.0"
   },
diff --git a/packages/@aws-cdk/aws-cloudtrail/test/test.cloudtrail.ts b/packages/@aws-cdk/aws-cloudtrail/test/test.cloudtrail.ts
index 3955ebc2c0488..ab8e8f2f06f5b 100644
--- a/packages/@aws-cdk/aws-cloudtrail/test/test.cloudtrail.ts
+++ b/packages/@aws-cdk/aws-cloudtrail/test/test.cloudtrail.ts
@@ -106,7 +106,7 @@ export = {
         const stack = getTestStack();
         new Trail(stack, 'MyAmazingCloudTrail', {
           sendToCloudWatchLogs: true,
-          cloudWatchLogsRetentionTimeDays: RetentionDays.ONE_WEEK
+          cloudWatchLogsRetention: RetentionDays.ONE_WEEK
         });
 
         expect(stack).to(haveResource("AWS::CloudTrail::Trail"));