Is there any way to get current time in nanoseconds using JavaScript?

Achieve microsecond accuracy in most browsers using:

window.performance.now()

See also:

• https://developer.mozilla.org/en-US/docs/Web/API/Performance.now()
• http://www.w3.org/TR/hr-time/
• https://caniuse.com/high-resolution-time

Building on Jeffery's answer, to get an absolute time-stamp (as the OP wanted) the code would be:

var TS = window.performance.timing.navigationStart + window.performance.now();

result is in millisecond units but is a floating-point value reportedly "accurate to one thousandth of a millisecond".