Luxon is a library for working with dates and times in Javascript

Luxon is a library for working with dates and times in Javascript

DateTime.local().setZone('America/New_York').minus({ weeks: 1 }).endOf('day').toISO();


Luxon started because I had a bunch of ideas on how to improve Moment but kept finding Moment wasn’t a good codebase to explore them with.


  • I wanted to try out some ideas that I thought would provide a better, more explicit API but didn’t want to break everything in Moment.

  • I had an idea on how to provide out-of-the-box, no-data-files-required support for time zones, but Moment’s design made that difficult.

  • I wanted to completely rethink how internationalization worked by using the Intl API that comes packaged in browsers.

  • I wanted to use a modern JS toolchain, which would require a major retrofit to Moment.

So I decided to write something from scratch, a sort of modernized Moment.

It’s a combination of all the things I learned maintaining Moment and Twix, plus a bunch of fresh ideas. I worked on it in little slivers of spare time for about two years.

But now it’s ready to actually use, and the Moment team likes it enough that we pulled it under the organization’s umbrella.

Ideas in Luxon

Luxon is built around a few core ideas:

  • Keep the basic chainable date wrapper idea from Moment.

  • Make all the types immutable.

  • Make the API explicit; different methods do different things and have well-defined options.

  • Use the Intl API to provide internationalization, including token parsing. Fall back to English if the browser doesn’t support those APIs.

  • Abuse the Intl API horribly to provide time zone support . Only possible for modern browsers.

  • Provide more comprehensive duration support .

  • Directly provide interval support.

  • Write inline docs for everything.

These ideas have some big advantages:

  • It’s much easier to understand and debug code that uses Luxon.

  • Using native browser capabilities for internationalization leads to a much better behavior and is dramatically easier to maintain.

  • Luxon has the best time zone support of any JS date library .

  • Luxon’s durations are both flexible and easy to use.

  • The documentation is very good.

They also have some disadvantages:

  • Using modern browser capabilities means that the fallback behavior introduces complexity for the programmer.

  • Never keeping internationalized strings in the code base means that some capabilities have to wait until the browsers provide it.

  • Some aspects of the Intl API are browser-dependent, which means Luxon’s behavior is too.

Future plans

Luxon is fully usable and I plan to support it indefinitely.

It’s also largely complete.

It will certainly add relative time formatting (and an English-only fallback) when that becomes possible.

Luxon will also eventually strip out its fallbacks for missing platform features. But overall I expect the core functionality to stay basically as it is, adding mostly minor tweaks and bugfixes.


  • DateTime, Duration, and Interval types.

  • Immutable, chainable, unambiguous API.

  • Parsing and formatting for common and custom formats.

  • Native time zone and Intl support (no locale or tz files) .