function FreshTime(){

                  var endtime=new Date('2019-4-12 18:00:00');//结束时间

                  var nowtime = new Date();//当前时间

                  var lefttime=parseInt((endtime.getTime()-nowtime.getTime())/1000);

                  d=parseInt(lefttime/3600/24);

                  h=parseInt((lefttime/3600)%24);

                  m=parseInt((lefttime/60)%60);

                  s=parseInt(lefttime%60);

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

                  if(lefttime<=0){

                      document.getElementById("Time").innerHTML="秒杀已结束";

                      clearInterval(hh);

                      $(".operate_btn").show()

                      }

                  }

                  FreshTime();

                  var hh;

                  hh=setInterval(FreshTime,1000);