The Date.now()
method returns the number of milliseconds elapsed since January 1, 1970 00:00:00 UTC.
Syntax
var timeInMs = Date.now();
Return value
A Number
representing the milliseconds elapsed since the UNIX epoch.
Description
Because now()
is a static method of Date
, you always use it as Date.now()
.
Polyfill
This method was standardized in ECMA-262 5th edition. Engines which have not been updated to support this method can work around the absence of this method using the following shim:
if (!Date.now) { Date.now = function now() { return new Date().getTime(); }; }
Specifications
Specification | Status | Comment |
---|---|---|
ECMAScript 5.1 (ECMA-262) The definition of 'Date.now' in that specification. |
Standard | Initial definition. Implemented in JavaScript 1.5. |
ECMAScript 2015 (6th Edition, ECMA-262) The definition of 'Date.now' in that specification. |
Standard | |
ECMAScript Latest Draft (ECMA-262) The definition of 'Date.now' in that specification. |
Living Standard |
Browser compatibility
The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
Feature | Chrome | Edge | Firefox | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|---|
Basic support | 5 | Yes | 3 | 9 | 10.5 | 4 |
Feature | Android webview | Chrome for Android | Edge mobile | Firefox for Android | IE mobile | Opera Android | iOS Safari |
---|---|---|---|---|---|---|---|
Basic support | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
See also
Performance.now()
— provides timestamps with sub-millisecond resolution for use in measuring web page performanceconsole.time()
/console.timeEnd()