Calculate difference between 2 timestamps using javascript

Based on the approved answer:

function(timestamp1, timestamp2) {
    var difference = timestamp1 - timestamp2;
    var daysDifference = Math.floor(difference/1000/60/60/24);

    return daysDifference;
}

i am posting my own example try implement this in your code

function timeDifference(date1,date2) {
    var difference = date1.getTime() - date2.getTime();

    var daysDifference = Math.floor(difference/1000/60/60/24);
    difference -= daysDifference*1000*60*60*24

    var hoursDifference = Math.floor(difference/1000/60/60);
    difference -= hoursDifference*1000*60*60

    var minutesDifference = Math.floor(difference/1000/60);
    difference -= minutesDifference*1000*60

    var secondsDifference = Math.floor(difference/1000);

    console.log('difference = ' + 
      daysDifference + ' day/s ' + 
      hoursDifference + ' hour/s ' + 
      minutesDifference + ' minute/s ' + 
      secondsDifference + ' second/s ');
}

A better alternative would be using window.performance API.

const startTime = window.performance.now()
setTimeout(()=>{
 const endTime = window.performance.now()
 console.log("Time Elapsed : ",endTime-startTime) // logs ~2000 milliseconds
}, 2000)