function getDateDiff(dateTimeStamp){
	  var minute = 1000 * 60;
	  var hour = minute * 60;
	  var day = hour * 24;
	  var halfamonth = day * 15;
	  var month = day * 30;
	  var now = new Date().getTime();
	  var diffValue = now - dateTimeStamp*1000;
	  if(diffValue < 0){return;}
	    var monthC =diffValue/month;
	    var weekC =diffValue/(7*day);
	    var dayC =diffValue/day;
	    var hourC =diffValue/hour;
	    var minC =diffValue/minute;
	    if(monthC>=1){
		      result="" + parseInt(monthC) + "月前";
	    }else if(weekC>=1){
		      result="" + parseInt(weekC) + "周前";
	    }else if(dayC>=1){
		      result=""+ parseInt(dayC) +"天前";
	    }else if(hourC>=1){
		      result=""+ parseInt(hourC) +"小时前";
	    }else if(minC>=1){
		      result=""+ parseInt(minC) +"分钟前";
	    }else
	      result="刚刚";
	      return result;
}
原文:http://www.cnblogs.com/SmqWord/p/6693853.html