raptor-polyfill/date/now.js

Polyfills for various EcmaScript 5 and EcmaScript 6 methods distributed as CommonJS modules that can be require'd individually or as a whole.

// ES5 15.9.4.4
// http://es5.github.com/#x15.9.4.4
if (!Date.now) {
   Date.now = function now() {
       return new Date().getTime();
   };
}