date: add dependencies for managing time zones

Add dependencies on third-party packages `chrono-tz` and
`iana-time-zone` to our `date` package. Together, these two packages
allow us to produce time zone abbreviations (like `UTC`) from numeric
timezone offsets.

Cargo.lock

@@ -302,6 +302,28 @@ dependencies = [
  "windows-targets 0.52.6",
 ]
 
+[[package]]
+name = "chrono-tz"
+version = "0.8.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d59ae0466b83e838b81a54256c39d5d7c20b9d7daa10510a242d9b75abd5936e"
+dependencies = [
+ "chrono",
+ "chrono-tz-build",
+ "phf",
+]
+
+[[package]]
+name = "chrono-tz-build"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "433e39f13c9a060046954e0592a8d0a4bcb1040125cbf91cb8ee58964cfb350f"
+dependencies = [
+ "parse-zoneinfo",
+ "phf",
+ "phf_codegen",
+]
+
 [[package]]
 name = "clang-sys"
 version = "1.8.1"
@@ -1582,6 +1604,15 @@ dependencies = [
  "windows-targets 0.52.6",
 ]
 
+[[package]]
+name = "parse-zoneinfo"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1f2a05b18d44e2957b88f96ba460715e295bc1d7510468a2f3d3b44535d26c24"
+dependencies = [
+ "regex",
+]
+
 [[package]]
 name = "parse_datetime"
 version = "0.6.0"
@@ -2590,7 +2621,9 @@ name = "uu_date"
 version = "0.0.29"
 dependencies = [
  "chrono",
+ "chrono-tz",
  "clap",
+ "iana-time-zone",
  "libc",
  "parse_datetime",
  "uucore",

Cargo.toml

@@ -280,6 +280,8 @@ chrono = { version = "0.4.38", default-features = false, features = [
 ] }
 clap = { version = "4.5", features = ["wrap_help", "cargo"] }
 clap_complete = "4.4"
+chrono-tz = "0.8.3"
+iana-time-zone = "0.1.57"
 clap_mangen = "0.2"
 compare = "0.1.0"
 coz = { version = "0.1.3" }

src/uu/date/Cargo.toml

@@ -22,6 +22,8 @@ chrono = { workspace = true }
 clap = { workspace = true }
 uucore = { workspace = true }
 parse_datetime = { workspace = true }
+chrono-tz = { workspace = true }
+iana-time-zone = { workspace = true }
 
 [target.'cfg(unix)'.dependencies]
 libc = { workspace = true }