On the standards track: Yes
Is Experimental: No
Is Deprecated: No
In Chrome version 1 on 2008-12-11 Note: Always returns 20030107.
In Chrome Android version 18 on 2012-06-27 Note: Always returns 20030107.
In Edge version 12 on 2015-07-29 Note: Always returns 20030107.
In Firefox version 1 on 2004-11-09
In Firefox for Android version 4 on 2011-03-29
Not in Internet Explorer
Not in Node.js
In Quest Browser version 5.0 on undefined Note: Always returns 20030107.
In Opera version 15 on 2013-07-02 Note: Always returns 20030107.
In Opera Android version 14 on 2013-05-21 Note: Always returns 20030107.
In Safari version 1 on 2003-06-23 Note: Always returns 20030107.
In Safari on iOS version 1 on 2007-06-29 Note: Always returns 20030107.
In Samsung Internet version 1.0 on 2013-04-27 Note: Always returns 20030107.
In WebView Android version 4.4 on 2013-12-09 Note: Always returns 20030107.
In WebView on iOS version 1 on 2007-06-29 Note: Always returns 20030107.