⚡

zdt

Datetime with Timezones in Zig. Opinionated, and mostly for learning purposes.

• API overview
• Roadmap
• Contributions: Welcome!

Demo

  // need an allocator for the time zones since the size of the rule-files varies
  var gpa = std.heap.GeneralPurposeAllocator(.{}){};
  defer _ = gpa.deinit();
  const allocator = gpa.allocator();

  // zdt embeds the IANA tz database:
  var tz_LA = try zdt.Timezone.fromTzdata("America/Los_Angeles", allocator);
  defer tz_LA.deinit();
  // you can also use your system's tz data if it provides it:
  var tz_Paris = try zdt.Timezone.fromTzfile("Europe/Paris", allocator);
  defer tz_Paris.deinit();

  // ISO8601 parser on-board, accepts wide variety of compatible formats
  const a_datetime = try zdt.Datetime.fromISO8601("2022-03-07");
  const this_time_LA = try a_datetime.tzLocalize(tz_LA);

  // string output also requires allocation...
  var buf = std.ArrayList(u8).init(allocator);
  defer buf.deinit();
  try this_time_LA.toString("%I %p, %Z", buf.writer());

  const this_time_Paris = try this_time_LA.tzConvert(tz_Paris);

  // '{s}' directive gives ISO8601 format by default;
  std.debug.print(
      "Time, LA : {s} ({s})\n... that's {s} in Paris\n\n",
      .{ this_time_LA, buf.items, this_time_Paris },
  );
  // Time, LA : 2022-03-07T00:00:00-08:00 (12 am, PST)
  // ... that's 2022-03-07T09:00:00+01:00 in Paris

  const wall_diff = try this_time_Paris.diffWall(this_time_LA);
  const abs_diff = this_time_Paris.diff(this_time_LA);

  std.debug.print(
      "Wall clock time difference: {s}\nAbsolute time difference: {s}\n",
      .{ wall_diff, abs_diff },
  );
  // Wall clock time difference: PT09H00M00S
  // Absolute time difference: PT00H00M00S

More examples in the ./examples directory. There's a build-step to build them all; EX:

zig build examples && ./zig-out/bin/ex_datetime

Documentation

See Wiki

Development

See changelog

Zig version

This library is developed with Zig 0.14.0-dev aka 'master', might not compile with older versions. As of 2024-10-01, Zig-0.13 stable or higher should work.

IANA timezone database version

• v0.2.2+ (current): 2024b
• >= v0.2.1: 2024a

Dependencies, Development and Time zone database

zdt comes with eggert/tz. The database is compiled and shipped with zdt (as-is; not tar-balled or compressed). If you wish to use your own version of the IANA time zone db, you can set a path to it using the -Dprefix-tzdb="path/to/your/tzdb" option. See also zig build --help

For development, to update the time zone database and the version info, run the following build steps: zig build update-tz-database && zig build update-tz-version. Some of the code generation is done with Python scripts, which require Python >= 3.9 but no third party packages, a system installation will do.

License

MPL. See the LICENSE file in the root directory of the repository.