用JS在页面上显示动态变化的时间

var s1 = "2015-3-10" ; //妈妈钱包上线时间
var s2 = nowDate; //今天的时间
var totalDays = DateDiff(s1,s2); //日期相减所得天数

            //计算天数差的函数，通用  
            function  DateDiff(sDate1,  sDate2){    //sDate1和sDate2是2002-12-18格式  
               var  aDate,  oDate1,  oDate2,  iDays;  
               aDate  =  sDate1.split("-")  ;
               oDate1  =  new  Date(aDate[1]  +  '-'  +  aDate[2]  +  '-'  +  aDate[0]) ;   //转换为12-18-2002格式  
               aDate  =  sDate2.split("-")  ;
               oDate2  =  new  Date(aDate[1]  +  '-'  +  aDate[2]  +  '-'  +  aDate[0])  ;
               iDays  =  parseInt(Math.abs(oDate1  -  oDate2)  /  1000  /  60  /  60  /24);    //把相差的毫秒数转换为天数  
               return  iDays;
            }
            
            //显示时间函数
            function displayTime(){
                $('p span').text(years);
                $('p em').text(remainDays);
                setInterval(function(){
                    $('p span').text(years);
                    $('p em').text(remainDays);
                    remainDays++;                       
                },3000)
            }
            if (731 < totalDays <= 1096) {
                var years = 2;
                var remainDays = totalDays - 731;                   
                displayTime();
            }else if(totalDays > 1096){                 
                var years = 3;
                var remainDays = totalDays - 1096;                  
                displayTime();                  
            }