Fix date histogram time zone for rollup index

src/plugins/data/common/search/aggs/buckets/date_histogram.ts

@@ -11,6 +11,7 @@ import moment from 'moment-timezone';
 import { i18n } from '@kbn/i18n';
 
 import { KBN_FIELD_TYPES, TimeRange, TimeRangeBounds, UI_SETTINGS } from '../../../../common';
+import { IFieldType } from '../../../index_patterns';
 
 import { intervalOptions, autoInterval, isAutoInterval } from './_interval_options';
 import { createFilterDateHistogram } from './create_filter/date_histogram';
@@ -58,7 +59,7 @@ export function isDateHistogramBucketAggConfig(agg: any): agg is IBucketDateHist
 }
 
 export interface AggParamsDateHistogram extends BaseAggParams {
-  field?: string;
+  field?: IFieldType | string;
   timeRange?: TimeRange;
   useNormalizedEsInterval?: boolean;
   scaleMetricValues?: boolean;

src/plugins/data/common/search/aggs/utils/infer_time_zone.test.ts

@@ -18,7 +18,7 @@ jest.mock('moment', () => {
   return moment;
 });
 
-import { IndexPattern } from '../../../index_patterns';
+import { IndexPattern, IndexPatternField } from '../../../index_patterns';
 import { AggParamsDateHistogram } from '../buckets';
 import { inferTimeZone } from './infer_time_zone';
 
@@ -51,6 +51,31 @@ describe('inferTimeZone', () => {
     ).toEqual('UTC');
   });
 
+  it('reads time zone from index pattern type meta if available when the field is not a string', () => {
+    expect(
+      inferTimeZone(
+        {
+          field: {
+            name: 'mydatefield',
+          } as IndexPatternField,
+        },
+        ({
+          typeMeta: {
+            aggs: {
+              date_histogram: {
+                mydatefield: {
+                  time_zone: 'UTC',
+                },
+              },
+            },
+          },
+        } as unknown) as IndexPattern,
+        () => false,
+        jest.fn()
+      )
+    ).toEqual('UTC');
+  });
+
   it('reads time zone from moment if set to default', () => {
     expect(inferTimeZone({}, {} as IndexPattern, () => true, jest.fn())).toEqual('CET');
   });

src/plugins/data/common/search/aggs/utils/infer_time_zone.ts

@@ -20,7 +20,8 @@ export function inferTimeZone(
   if (!tz && params.field) {
     // If a field has been configured check the index pattern's typeMeta if a date_histogram on that
     // field requires a specific time_zone
-    tz = indexPattern.typeMeta?.aggs?.date_histogram?.[params.field]?.time_zone;
+    const fieldName = typeof params.field === 'string' ? params.field : params.field.name;
+    tz = indexPattern.typeMeta?.aggs?.date_histogram?.[fieldName]?.time_zone;
   }
   if (!tz) {
     // If the index pattern typeMeta data, didn't had a time zone assigned for the selected field use the configured tz