Momentjs

Moment.js is a JavaScript library that provides utilities for parsing, validating, manipulating, and displaying dates and times in JavaScript applications. It is widely used in both web browsers and Node.js environments and offers a simple, chainable API for common date-time operations. Moment.js objects are mutable by default, meaning methods commonly modify the original moment instance, though a clone method is available to work with copies. The project was created by Tim Wood and has been distributed under the MIT license.

Key features include parsing and validating date strings from various formats (including ISO 8601 and RFC 2822), formatting dates using a rich set of tokens, and performing calculations such as adding or subtracting time, computing differences, and producing relative or calendar time representations. It also supports durations and human-friendly output like relative time (for example, “in 3 days” or “2 hours ago”). Internationalization is supported through locale data, and time zone handling can be extended with the moment-timezone plugin. A large ecosystem of plugins adds additional functionality, and Moment.js is usable via a script tag in browsers or through npm for Node.js projects.

Maintenance status and alternatives: In 2020, the Moment.js team announced that Moment.js is a legacy project in maintenance mode. It will continue to receive bug fixes and critical updates but not new features. For new projects, the team recommends evaluating modern alternatives that emphasize immutability, modular design, or improved performance, such as Luxon, date-fns, and Day.js, among others.

Usage example: moment().format('YYYY-MM-DD') demonstrates typical formatting, while moment('2024-01-01').add(7, 'days') shows arithmetic on dates.