Almost any kind of application written in JavaScript works with times or dates in some capacity. In the beginning, this was limited to the built-in Date API. This API includes basic functionality, but is quite limited in what it can do. Third-party libraries like Moment.js, and later built-in APIs such as the Intl APIs and the new Temporal API , add much greater flexibility to working with times and dates. The Rise And Fall Of Moment.js Moment.js is a JavaScript library with powerful utilities for working with times and dates. It includes missing features from the basic Date API , such as time zone manipulation, and makes many common operations simpler. Moment also includes functions for formatting dates and times. It became a widely used library in many different applications. However, Moment also had its share of issues. It’s a large library, and can add significantly to an application