JavaScript's Date object has carried the web for decades, but almost every experienced developer has a story about it: an off-by-one-day bug, a daylight-saving surprise, a month numbered from zero, or a date-only value that silently became a timestamp.
In July 2026, the TC39 Temporal proposal reached a Stage 4 draft. That is a major standardisation milestone: the API has completed the proposal process and is ready to become part of the ECMAScript standard.
But Stage 4 does not mean you can assume every current browser already has Temporal. MDN still marks the API as limited availability. The practical approach is to learn the model now, use feature detection, and add the official polyfill when your support policy requires it.
This guide explains the mental model, the most useful types, and a safe migration path from Date.
What you will learn
