Returns the number of milliseconds, accurate to a thousandth of a millisecond, from the start of document navigation to the time the now method was called.
Syntaxvar retVal = performance.now();
- retVal [out, retval]
When taking web application performance measurements, use this method instead of the Date.now method to ensure that the returned timing values have a millisecond resolution and monotonically increase (where later values are never less than earlier values).
Build date: 11/17/2013