Compliments of
This answer
var currentTime = new Date()
var currDate = currentTime.getMonth() + 1 + "/" + currentTime.getDate() + "/" + currentTime.getFullYear()
var iniPastedDate = "8/7/2012"
function DateDiff(date1, date2) {
var datediff = date1.getTime() - date2.getTime();
return (datediff / (24*60*60*1000));
}
document.write (DateDiff(new Date(iniPastedDate),new Date(currDate)));
The only thing you have to do from this answer is to get the month diff value.