The bane of many a developer’s existence is dates and times. When building a JavaScript app that needs to deal with time, you probably want to save yourself the headache and will reach for a DateTime library to handle it for you.
Years ago, the clear answer was moment.js. With its exhaustive feature set and excellent support for internationalization, it was the de facto standard. Today, it is no longer actively developed. Avoid it when possible. Now, deciding between the available options can be as much a headache as dealing with date/time manipulation yourself.
Luxon
Luxon was built by a former developer of Moment.js and is intended as a modern replacement. It’s built on top of JavaScript’s `Intl` API, and so it has excellent internationalization support similar to Moment.js. It has a robust set of features to support a variety of use cases.
It shines in its ability to handle conversions between time zones easily and is a great choice for apps requiring accurate time zone handling. Its internationalization support allows for easy formatting of dates and times to local formats.
date-fns
The date-fns library consists of pure utility functions that build on JavaScript’s `Date`. It’s useful for apps where there is more concern over bundle size. Each function is its own standalone import, making it flexible and easy to optimize with.
date-fns does fall a bit short when it comes to handling internationalization. While it has support for conversion between time zones and formatting, it’s not as easy to manage as with Luxon. date-fns is an excellent option when various functions are needed to handle a variety of date and time logic needs, and when timezones and localization aren’t as important.
Day.js
Day.js is a minimalist library that closely resembles Moment.js in use while having by far the smallest (~2KB) bundle size of all options considered here. It is lightweight and easy to use but doesn’t have as rich a feature set as the others.
It can be extended with a large ecosystem of plugins, allowing developers to include only what they require. It’s a great choice for those who want to use a library that is similar to Moment.js, value performance and size, and only requires more basic date/time manipulation.
Which of the major date/time libraries is best for your use case?