JavaScript Date Get the number of milliseconds elapsed since 1 January 1970 00:00:00 UTC
Example
The static method Date.now returns the number of milliseconds that have elapsed since 1 January 1970 00:00:00 UTC. To get the number of milliseconds that have elapsed since that time using an instance of a Date object, use its getTime method.
// get milliseconds using static method now of Date
console.log(Date.now());
// get milliseconds using method getTime of Date instance
console.log((new Date()).getTime());
