how to get the timestamp in milisec in js with time selected by user code example

Example 1: javascript get timestamp

var currentTimeInSeconds=Math.floor(Date.now()/1000); //unix timestamp in seconds
var currentTimeInMilliseconds=Date.now(); // unix timestamp in milliseconds

Example 2: how to get the timestamp in javascript

const currentTimeInMilliseconds=Date.now(); // unix timestamp in milliseconds