Calculate date difference in JavaScript

In this article you will learn how to calculate the number of days between two different date range in javascript.

<script language="javascript" type="text/javascript">

var start_date = "2009-10-01".split("-");
var end_date = "2009-10-06".split("-");


var date1 = new Date(start_date[0], start_date[1]-1, start_date[2]);
var date2 = new Date(end_date[0], end_date[1]-1, end_date[2]);

var ONE_DAY = (1000 * 60 * 60 * 24); // The number of milliseconds in one day

// Convert both dates to milliseconds
var date1_ms = date1.getTime();
var date2_ms = date2.getTime();

var difference_ms = Math.abs(date1_ms - date2_ms);  // Calculate the difference in milliseconds
var date_diff = Math.round(difference_ms/ONE_DAY)+1; // Convert back to days and return

alert (date_diff);

</script>