Date.now()

The Date.now() method returns the number of milliseconds elapsed since 1 January 1970 00:00:00 UTC.

Syntax

JavaScript
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:

JavaScript
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 2017 Draft (ECMA-262)
The definition of 'Date.now' in that specification.
Draft  

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support 5 3.0 (1.9) 9 10.50 4
Feature Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support (Yes) (Yes) (Yes) (Yes) (Yes) (Yes)

See also

License

© 2016 Mozilla Contributors
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

Date JavaScript Method polyfill Reference