Moving From Moment.js To The JS Temporal API

This article provides practical migration recipes for moving from Moment.js to the new JavaScript Temporal API, which reached TC39 Stage 4 in March 2026.

• •Moment.js is now in maintenance mode due to large bundle size, lack of tree-shaking support, and mutable objects that cause unexpected side effects.
• •Temporal is built into the browser (Chrome 144+, Firefox 139+), adds zero bundle size, and uses immutable objects for all date/time operations.
• •Temporal fixes the long-standing zero-indexed months bug by using 1-based indexing (January = 1).
• •Key object types include Temporal.Instant, Temporal.PlainDate, Temporal.PlainTime, and Temporal.ZonedDateTime, each representing different levels of date/time precision.
• •Temporal only accepts ISO 8601 or RFC 9557 formatted strings and throws a RangeError for non-compliant inputs, unlike Moment's lenient parsing.