The Date.now()
method returns the number of milliseconds elapsed since January 1, 1970 00:00:00 UTC.
var timeInMs = Date.now();
A Number
representing the milliseconds elapsed since the UNIX epoch.
Because now()
is a static method of Date
, you always use it as Date.now()
.
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(); }; }
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. | Draft |
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 | Opera Android | iOS Safari | Samsung Internet |
---|---|---|---|---|---|---|---|
Basic support | Yes | Yes | Yes | Yes | Yes | Yes | ? |
Performance.now()
— provides timestamps with sub-millisecond resolution for use in measuring web page performanceconsole.time()
/ console.timeEnd()
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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/now