js-Joda

js-joda is an immutable date and time library for JavaScript. It provides a simple, domain-driven and clean API based on the ISO calendar system, which is the de facto world calendar following the proleptic Gregorian rules.

js-joda has a lightweight footprint, only 43 kB minified and compressed, no third party dependencies.

js-joda is fast. It is about 2 to 10 times faster than other JavaScript date libraries.

js-joda comes with built-in parsers/ formatters for ISO 8601 as specified in RFC 3339, that can be easily customized.

js-joda supports ECMAScript 5 browsers down to IE9.

js-joda is a port of the threeten backport, which is the base for JSR-310 implementation of the Java SE 8 java.time package. Threeten is inspired by Joda-Time, having similar concepts and the same author.

js-joda is robust and stable. We ported more then 1700 test-cases with a lots of test-permutations from the threetenbp project. We run the automated karma test-suite against Firefox, Chrome, Node and phantomjs.

Why yet another javascript date and time library

Popular javascript date libraries like moment or date-utils are wrappers around the native javascript Date object, providing syntactic sugar. The native Date object always consist of a date, time and a timezone part. In opposite to that, js-joda is a standalone date and time implementation.

The API has a domain-driven design with classes for the different use cases, like LocalDate, ZonedDateTime or Period. For examples LocalDate allows to handle dates like birthdays or holidays in a clean and error-safe way, especially if these dates are persisted to an external server.

js-joda is immutable. Immutability aligns well with pure functions and with the architecture of frameworks like React and Flux.