JS :: Calculate Time Since

function getTimeSince(start, end) {
	var msSince = (end - start);

	var msInDay = 24*60*60*1000
	  , msInHour = 60*60*1000
	  , msInMinute = 60*1000
	  , msInSecond = 1000;

	if (msSince > msInDay) { // greater than one day
		return parseInt(msSince / msInDay).toString() + 'd Ago';
	} else if (msSince > msInHour) { // greater than one hour
		return parseInt(msSince / msInHour).toString() + 'h Ago';
	} else if (msSince > msInMinute) { // greater than one minute
		return parseInt(msSince / msInMinute).toString() + 'm Ago';
	} else { // seconds ago
		var sSince = parseInt(msSince / msInSecond);

		if (sSince > 0) {
			return sSince.toString() + 's Ago';	
		} else {
			return "Just Now";
		}
	}
};