We would like to know how to calculate days since Dec 1st 2012.
<!DOCTYPE html>
<html>
<body>
<p>Days since Dec. 1st, 2012: <span id="days_since"></span></p>
<!-- w w w .j ava 2 s . com-->
<script type='text/javascript'>
//
var initialDate = new Date(2012, 11, 1); // Dec 1st 2012
var now = Date.now();
var difference = now - initialDate;
var millisecondsPerDay = 24 * 60 * 60 * 1000;
var daysSince = Math.floor(difference / millisecondsPerDay);
document.getElementById('days_since').innerHTML = daysSince;
</script>
</body>
</html>
The code above is rendered as follows: