Javascript return number of days,hours,minutes,seconds between two dates

Does anyone can link me to some tutorial where I can find out how to return days , hours , minutes, seconds in javascript between 2 unix datetimes?

I have:

var date_now = unixtimestamp;
var date_future = unixtimestamp;

I would like to return (live) how many days,hours,minutes,seconds left from the date_now to the date_future.

Answer

Just figure out the difference in seconds (don’t forget JS timestamps are actually measured in milliseconds) and decompose that value:

// get total seconds between the times
var delta = Math.abs(date_future - date_now) / 1000;

// calculate (and subtract) whole days
var days = Math.floor(delta / 86400);
delta -= days * 86400;

// calculate (and subtract) whole hours
var hours = Math.floor(delta / 3600) % 24;
delta -= hours * 3600;

// calculate (and subtract) whole minutes
var minutes = Math.floor(delta / 60) % 60;
delta -= minutes * 60;

// what's left is seconds
var seconds = delta % 60;  // in theory the modulus is not required

EDIT code adjusted because I just realised that the original code returned the total number of hours, etc, not the number of hours left after counting whole days.