diff --git a/packages/os/Cargo.toml b/packages/os/Cargo.toml
index 23fa8a594b3..c719124543a 100644
--- a/packages/os/Cargo.toml
+++ b/packages/os/Cargo.toml
@@ -10,6 +10,7 @@ variant-sensitive = true
 source-groups = [
     "api",
     "bottlerocket-release",
+    "parse-datetime",
     "growpart",
     "updater",
     "webpki-roots-shim",
diff --git a/sources/Cargo.lock b/sources/Cargo.lock
index 307ab364efa..5dfaa005c81 100644
--- a/sources/Cargo.lock
+++ b/sources/Cargo.lock
@@ -46,7 +46,7 @@ dependencies = [
  "base64 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "bitflags 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "bytes 0.5.4 (registry+https://github.com/rust-lang/crates.io-index)",
- "chrono 0.4.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "chrono 0.4.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "copyless 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "derive_more 0.99.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "either 1.5.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -270,7 +270,7 @@ dependencies = [
  "http 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "hyper 0.13.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "hyper-unix-connector 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
- "snafu 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "snafu 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "tokio 0.2.13 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -292,7 +292,7 @@ dependencies = [
  "serde 1.0.104 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.48 (registry+https://github.com/rust-lang/crates.io-index)",
  "simplelog 0.7.4 (registry+https://github.com/rust-lang/crates.io-index)",
- "snafu 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "snafu 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "toml 0.5.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "walkdir 2.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -436,7 +436,7 @@ dependencies = [
 name = "block-party"
 version = "0.1.0"
 dependencies = [
- "snafu 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "snafu 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -456,7 +456,7 @@ dependencies = [
  "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "semver 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.104 (registry+https://github.com/rust-lang/crates.io-index)",
- "snafu 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "snafu 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -543,7 +543,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "chrono"
-version = "0.4.10"
+version = "0.4.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "num-integer 0.1.42 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -726,7 +726,7 @@ dependencies = [
  "serde 1.0.104 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.48 (registry+https://github.com/rust-lang/crates.io-index)",
  "simplelog 0.7.4 (registry+https://github.com/rust-lang/crates.io-index)",
- "snafu 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "snafu 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "toml 0.5.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -1002,7 +1002,7 @@ dependencies = [
  "cargo-readme 3.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "gptman 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.67 (registry+https://github.com/rust-lang/crates.io-index)",
- "snafu 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "snafu 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -1086,7 +1086,7 @@ dependencies = [
  "serde 1.0.104 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.48 (registry+https://github.com/rust-lang/crates.io-index)",
  "simplelog 0.7.4 (registry+https://github.com/rust-lang/crates.io-index)",
- "snafu 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "snafu 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -1261,7 +1261,7 @@ version = "0.1.0"
 dependencies = [
  "cargo-readme 3.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "filetime 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "snafu 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "snafu 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "sys-mount 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -1362,7 +1362,7 @@ dependencies = [
  "schnauzer 0.1.0",
  "serde 1.0.104 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.48 (registry+https://github.com/rust-lang/crates.io-index)",
- "snafu 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "snafu 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "toml 0.5.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -1379,7 +1379,7 @@ dependencies = [
  "regex 1.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "semver 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "simplelog 0.7.4 (registry+https://github.com/rust-lang/crates.io-index)",
- "snafu 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "snafu 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -1457,7 +1457,7 @@ dependencies = [
  "model-derive 0.1.0",
  "regex 1.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.104 (registry+https://github.com/rust-lang/crates.io-index)",
- "snafu 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "snafu 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "toml 0.5.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "url 2.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -1485,7 +1485,7 @@ dependencies = [
  "regex 1.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.104 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_plain 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "snafu 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "snafu 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -1589,6 +1589,15 @@ dependencies = [
  "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "parse-datetime"
+version = "0.1.0"
+dependencies = [
+ "cargo-readme 3.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "chrono 0.4.11 (registry+https://github.com/rust-lang/crates.io-index)",
+ "snafu 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "pem"
 version = "0.7.0"
@@ -1683,7 +1692,7 @@ dependencies = [
  "cargo-readme 3.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "reqwest 0.10.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.48 (registry+https://github.com/rust-lang/crates.io-index)",
- "snafu 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "snafu 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -2011,7 +2020,7 @@ dependencies = [
  "models 0.1.0",
  "serde 1.0.104 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.48 (registry+https://github.com/rust-lang/crates.io-index)",
- "snafu 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "snafu 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -2122,7 +2131,7 @@ dependencies = [
  "serde 1.0.104 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.48 (registry+https://github.com/rust-lang/crates.io-index)",
  "simplelog 0.7.4 (registry+https://github.com/rust-lang/crates.io-index)",
- "snafu 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "snafu 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -2136,7 +2145,7 @@ dependencies = [
  "serde 1.0.104 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.48 (registry+https://github.com/rust-lang/crates.io-index)",
  "simplelog 0.7.4 (registry+https://github.com/rust-lang/crates.io-index)",
- "snafu 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "snafu 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -2183,7 +2192,7 @@ dependencies = [
  "hex-literal 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.104 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_plain 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "snafu 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "snafu 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -2191,7 +2200,7 @@ name = "simplelog"
 version = "0.7.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "chrono 0.4.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "chrono 0.4.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "term 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -2223,16 +2232,17 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "snafu"
-version = "0.6.2"
+version = "0.6.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
+ "backtrace 0.3.44 (registry+https://github.com/rust-lang/crates.io-index)",
  "doc-comment 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "snafu-derive 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "snafu-derive 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "snafu-derive"
-version = "0.6.2"
+version = "0.6.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "proc-macro2 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2273,7 +2283,7 @@ dependencies = [
  "rand 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "semver 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "simplelog 0.7.4 (registry+https://github.com/rust-lang/crates.io-index)",
- "snafu 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "snafu 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "toml 0.5.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -2322,7 +2332,7 @@ dependencies = [
  "serde 1.0.104 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.48 (registry+https://github.com/rust-lang/crates.io-index)",
  "simplelog 0.7.4 (registry+https://github.com/rust-lang/crates.io-index)",
- "snafu 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "snafu 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -2420,7 +2430,7 @@ dependencies = [
  "schnauzer 0.1.0",
  "serde_json 1.0.48 (registry+https://github.com/rust-lang/crates.io-index)",
  "simplelog 0.7.4 (registry+https://github.com/rust-lang/crates.io-index)",
- "snafu 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "snafu 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -2515,7 +2525,7 @@ name = "tough"
 version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "chrono 0.4.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "chrono 0.4.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "hex 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "olpc-cjson 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "pem 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2524,7 +2534,7 @@ dependencies = [
  "serde 1.0.104 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.48 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_plain 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "snafu 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "snafu 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "untrusted 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "url 2.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -2634,7 +2644,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 name = "update_metadata"
 version = "0.1.0"
 dependencies = [
- "chrono 0.4.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "chrono 0.4.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "migrator 0.1.0",
  "rand 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex 1.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2642,7 +2652,7 @@ dependencies = [
  "serde 1.0.104 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.48 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_plain 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "snafu 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "snafu 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -2650,7 +2660,7 @@ name = "updog"
 version = "0.1.0"
 dependencies = [
  "bottlerocket-release 0.1.0",
- "chrono 0.4.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "chrono 0.4.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "lz4 1.23.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "migrator 0.1.0",
@@ -2664,7 +2674,7 @@ dependencies = [
  "signal-hook 0.1.13 (registry+https://github.com/rust-lang/crates.io-index)",
  "signpost 0.1.0",
  "simplelog 0.7.4 (registry+https://github.com/rust-lang/crates.io-index)",
- "snafu 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "snafu 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "structopt 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)",
  "tempfile 3.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "toml 0.5.6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2956,7 +2966,7 @@ dependencies = [
 "checksum cargo_metadata 0.6.4 (registry+https://github.com/rust-lang/crates.io-index)" = "e5d1b4d380e1bab994591a24c2bdd1b054f64b60bef483a8c598c7c345bc3bbe"
 "checksum cc 1.0.50 (registry+https://github.com/rust-lang/crates.io-index)" = "95e28fa049fda1c330bcf9d723be7663a899c4679724b34c81e9f5a326aab8cd"
 "checksum cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)" = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
-"checksum chrono 0.4.10 (registry+https://github.com/rust-lang/crates.io-index)" = "31850b4a4d6bae316f7a09e691c944c28299298837edc0a03f755618c23cbc01"
+"checksum chrono 0.4.11 (registry+https://github.com/rust-lang/crates.io-index)" = "80094f509cf8b5ae86a4966a39b3ff66cd7e2a3e594accec3743ff3fabeab5b2"
 "checksum clap 2.33.0 (registry+https://github.com/rust-lang/crates.io-index)" = "5067f5bb2d80ef5d68b4c87db81601f0b75bca627bc2ef76b141d7b846a3c6d9"
 "checksum cloudabi 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "ddfc5b9aa5d4507acaf872de71051dfd0e309860e88966e1051e462a077aac4f"
 "checksum constant_time_eq 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "245097e9a4535ee1e3e3931fcfcd55a796a44c643e8596ff6566d68f09b87bbc"
@@ -3124,8 +3134,8 @@ dependencies = [
 "checksum skeptic 0.13.4 (registry+https://github.com/rust-lang/crates.io-index)" = "d6fb8ed853fdc19ce09752d63f3a2e5b5158aeb261520cd75eb618bd60305165"
 "checksum slab 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "c111b5bd5695e56cffe5129854aa230b39c93a305372fdbb2668ca2394eea9f8"
 "checksum smallvec 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "5c2fb2ec9bcd216a5b0d0ccf31ab17b5ed1d627960edff65bbe95d3ce221cefc"
-"checksum snafu 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)" = "546db9181bce2aa22ed883c33d65603b76335b4c2533a98289f54265043de7a1"
-"checksum snafu-derive 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)" = "bdc75da2e0323f297402fd9c8fdba709bb04e4c627cbe31d19a2c91fc8d9f0e2"
+"checksum snafu 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)" = "48492e4f51c6e679217e80c11290edfdedf3133e358f4f432a6296f4c820f95b"
+"checksum snafu-derive 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)" = "b5d1c41856cbfa99befda5034c72539dd9d7dd6f3e61058bdb804ac40715bc2a"
 "checksum socket2 0.3.11 (registry+https://github.com/rust-lang/crates.io-index)" = "e8b74de517221a2cb01a53349cf54182acdc31a074727d3079068448c0676d85"
 "checksum sourcefile 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "4bf77cb82ba8453b42b6ae1d692e4cdc92f9a47beaf89a847c8be83f4e328ad3"
 "checksum spin 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)" = "6e63cff320ae2c57904679ba7cb63280a3dc4613885beafb148ee7bf9aa9042d"
diff --git a/sources/Cargo.toml b/sources/Cargo.toml
index 23f7a7221e6..f7e5d74c579 100644
--- a/sources/Cargo.toml
+++ b/sources/Cargo.toml
@@ -24,6 +24,8 @@ members = [
 
     "models",
 
+    "parse-datetime",
+
     "preinit/laika",
 
     "updater/block-party",
diff --git a/sources/parse-datetime/Cargo.toml b/sources/parse-datetime/Cargo.toml
new file mode 100644
index 00000000000..f67620a8f8f
--- /dev/null
+++ b/sources/parse-datetime/Cargo.toml
@@ -0,0 +1,14 @@
+[package]
+name = "parse-datetime"
+version = "0.1.0"
+authors = ["Zac Mrowicki <mrowicki@amazon.com>"]
+license = "Apache-2.0 OR MIT"
+edition = "2018"
+publish = false
+
+[dependencies]
+chrono = "0.4.11"
+snafu = { version = "0.6.3", features = ["backtraces-impl-backtrace-crate"] }
+
+[build-dependencies]
+cargo-readme = "3.1"
diff --git a/sources/parse-datetime/README.md b/sources/parse-datetime/README.md
new file mode 100644
index 00000000000..33258616879
--- /dev/null
+++ b/sources/parse-datetime/README.md
@@ -0,0 +1,25 @@
+# parse-datetime
+
+Current version: 0.1.0
+
+## Background
+
+This library parses a `DateTime<Utc>` from a string.
+
+The string can be:
+
+* an `RFC3339` formatted date / time
+* a string with the form `"in <unsigned integer> <unit(s)>"` where
+   * `<unsigned integer>` may be any unsigned integer and
+   * `<unit(s)>` may be either the singular or plural form of the following: `hour | hours`, `day | days`, `week | weeks`
+
+Examples:
+
+* `"in 1 hour"`
+* `"in 2 hours"`
+* `"in 6 days"`
+* `"in 2 weeks"`
+
+## Colophon
+
+This text was generated from `README.tpl` using [cargo-readme](https://crates.io/crates/cargo-readme), and includes the rustdoc from `src/lib.rs`.
\ No newline at end of file
diff --git a/sources/parse-datetime/README.tpl b/sources/parse-datetime/README.tpl
new file mode 100644
index 00000000000..91fb62910c8
--- /dev/null
+++ b/sources/parse-datetime/README.tpl
@@ -0,0 +1,9 @@
+# {{crate}}
+
+Current version: {{version}}
+
+{{readme}}
+
+## Colophon
+
+This text was generated from `README.tpl` using [cargo-readme](https://crates.io/crates/cargo-readme), and includes the rustdoc from `src/lib.rs`.
diff --git a/sources/parse-datetime/build.rs b/sources/parse-datetime/build.rs
new file mode 100644
index 00000000000..4eec4b80b5e
--- /dev/null
+++ b/sources/parse-datetime/build.rs
@@ -0,0 +1,45 @@
+// Automatically generate README.md from rustdoc.
+
+use std::env;
+use std::fs::{self, File};
+use std::io::Write;
+use std::path::{Path, PathBuf};
+
+fn generate_readme() {
+    // Check for environment variable "SKIP_README". If it is set,
+    // skip README generation
+    if env::var_os("SKIP_README").is_some() {
+        return;
+    }
+
+    let mut source = File::open("src/lib.rs").unwrap();
+    let mut template = File::open("README.tpl").unwrap();
+
+    let content = cargo_readme::generate_readme(
+        &PathBuf::from("."), // root
+        &mut source,         // source
+        Some(&mut template), // template
+        // The "add x" arguments don't apply when using a template.
+        true,  // add title
+        false, // add badges
+        false, // add license
+        true,  // indent headings
+    )
+    .unwrap();
+
+    let mut readme = File::create("README.md").unwrap();
+    readme.write_all(content.as_bytes()).unwrap();
+}
+
+fn generate_constants() {
+    let out_dir = env::var("OUT_DIR").unwrap();
+    let arch = env::var("CARGO_CFG_TARGET_ARCH").unwrap();
+    let contents = format!("const ARCH: &str = \"{}\";", arch);
+    let path = Path::new(&out_dir).join("constants.rs");
+    fs::write(path, contents).unwrap();
+}
+
+fn main() {
+    generate_readme();
+    generate_constants();
+}
diff --git a/sources/parse-datetime/src/lib.rs b/sources/parse-datetime/src/lib.rs
new file mode 100644
index 00000000000..38f79798632
--- /dev/null
+++ b/sources/parse-datetime/src/lib.rs
@@ -0,0 +1,130 @@
+/*!
+# Background
+
+This library parses a `DateTime<Utc>` from a string.
+
+The string can be:
+
+* an `RFC3339` formatted date / time
+* a string with the form `"in <unsigned integer> <unit(s)>"` where
+   * `<unsigned integer>` may be any unsigned integer and
+   * `<unit(s)>` may be either the singular or plural form of the following: `hour | hours`, `day | days`, `week | weeks`
+
+Examples:
+
+* `"in 1 hour"`
+* `"in 2 hours"`
+* `"in 6 days"`
+* `"in 2 weeks"`
+*/
+
+use chrono::{DateTime, Duration, FixedOffset, Utc};
+use snafu::{ensure, ResultExt};
+
+mod error {
+    use snafu::Snafu;
+
+    #[derive(Debug, Snafu)]
+    #[snafu(visibility = "pub(super)")]
+    pub enum Error {
+        #[snafu(display("Date argument '{}' is invalid: {}", input, msg))]
+        DateArgInvalid { input: String, msg: &'static str },
+
+        #[snafu(display(
+            "Date argument had count '{}' that failed to parse as integer: {}",
+            input,
+            source
+        ))]
+        DateArgCount {
+            input: String,
+            source: std::num::ParseIntError,
+        },
+    }
+}
+pub use error::Error;
+type Result<T> = std::result::Result<T, error::Error>;
+
+/// Parses a user-specified datetime, either in full RFC 3339 format, or a shorthand like "in 7
+/// days"
+pub fn parse_datetime(input: &str) -> Result<DateTime<Utc>> {
+    // If the user gave an absolute date in a standard format, accept it.
+    let try_dt: std::result::Result<DateTime<FixedOffset>, chrono::format::ParseError> =
+        DateTime::parse_from_rfc3339(input);
+    if let Ok(dt) = try_dt {
+        let utc = dt.into();
+        return Ok(utc);
+    }
+
+    // Otherwise, pull apart a request like "in 5 days" to get an exact datetime.
+    let mut parts: Vec<&str> = input.split_whitespace().collect();
+    ensure!(
+        parts.len() == 3,
+        error::DateArgInvalid {
+            input,
+            msg: "expected RFC 3339, or something like 'in 7 days'"
+        }
+    );
+    let unit_str = parts.pop().unwrap();
+    let count_str = parts.pop().unwrap();
+    let prefix_str = parts.pop().unwrap();
+
+    ensure!(
+        prefix_str == "in",
+        error::DateArgInvalid {
+            input,
+            msg: "expected RFC 3339, or prefix 'in', something like 'in 7 days'",
+        }
+    );
+
+    let count: u32 = count_str.parse().context(error::DateArgCount { input })?;
+
+    let duration = match unit_str {
+        "hour" | "hours" => Duration::hours(i64::from(count)),
+        "day" | "days" => Duration::days(i64::from(count)),
+        "week" | "weeks" => Duration::weeks(i64::from(count)),
+        _ => {
+            return error::DateArgInvalid {
+                input,
+                msg: "date argument's unit must be hours/days/weeks",
+            }
+            .fail();
+        }
+    };
+
+    let now = Utc::now();
+    let then = now + duration;
+    Ok(then)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_acceptable_strings() {
+        let inputs = vec![
+            "in 0 hours",
+            "in 1 hour",
+            "in 5000000 hours",
+            "in 0 days",
+            "in 1 day",
+            "in 5000000 days",
+            "in 0 weeks",
+            "in 1 week",
+            "in 5000000 weeks",
+        ];
+
+        for input in inputs {
+            assert!(parse_datetime(input).is_ok())
+        }
+    }
+
+    #[test]
+    fn test_unacceptable_strings() {
+        let inputs = vec!["in", "0 hours", "hours", "in 1 month"];
+
+        for input in inputs {
+            assert!(parse_datetime(input).is_err())
+        }
+    }
+}