jquery前端倒计时

    function FreshTime(){

    // var endtime=new Date("2019/04/15,12:20:12");//结束时间
    var endtime = $("#time").val()
    var endtime=new Date(endtime)
    // alert(endtime)
    var nowtime = new Date();//当前时间
    var lefttime= parseInt((endtime.getTime()-nowtime.getTime())/1000); 
    d=parseInt(lefttime/3600/24); ;
    h= parseInt(lefttime/(60*60))%24 ;
    m= parseInt(lefttime/(60))%60 ;
    s= parseInt(lefttime%60);

    document.getElementById("LeftTime").innerHTML=d+"天"+h+"小时"+m+"分"+s+"秒";

    if(lefttime < 0){
    document.getElementById("LeftTime").innerHTML="秒杀已结束";
    clearInterval(sh);
    }
}
FreshTime()
var sh;
sh=setInterval(FreshTime,1000);