js根据服务端返回的时间倒计时

使用服务端与本地的时间差进行计算

$(function(){
???// 倒计时
???var _ordertimer = null;
???var data =new Date();
???var txt = $(‘.js_time_txt‘);
???var buyTime = ‘2018/03/28 10:30:00‘; //开抢时间
???var nowTime = ‘2018/03/16 17:00:00‘; //接口返回当前时间

???var dateDiff = new Date(nowTime) - new Date(getnow()); //请求时间戳与本地时间戳
???if(dateDiff < 0 ){
???????dateDiff = Math.abs(dateDiff);
???}

???if(new Date(nowTime) > new Date(buyTime)){
???????$(‘.time-range‘).hide(); //已开枪
???????return;
???} else{
???????leftTimer(buyTime);
???????_ordertimer = setInterval(function(){leftTimer(buyTime)}, 1000);
???}

???// 获取当前时间 xxxx/xx/xx 00:00:00
???function getnow(){
???????var year = data.getFullYear();
???????var month = parseInt(data.getMonth()+1) >= 10 ? parseInt(data.getMonth()+1) : ‘0‘ + parseInt(data.getMonth()+1);
???????var day = data.getDate();
???????var hours = ?data.getHours(); ?
???????var minutes = ?data.getMinutes();
???????var seconds = ?data.getSeconds(); ?
???????var now = year +‘/‘+ month +‘/‘+ day +‘ ‘+ hours +‘:‘+ minutes +‘:‘+ seconds;
???????return now;
???}

???function leftTimer(enddate) {

?????var leftTime = (new Date(enddate)) - new Date + dateDiff;

???  var days = parseInt(leftTime / 1000 / 60 / 60 / 24, 10); //计算剩余的天数
???  var hours = parseInt(leftTime / 1000 / 60 / 60 % 24, 10); //计算剩余的小时
???  var minutes = parseInt(leftTime / 1000 / 60 % 60, 10);//计算剩余的分钟
???  var seconds = parseInt(leftTime / 1000 % 60, 10);//计算剩余的秒数
???  days = checkTime(days);
???  hours = checkTime(hours);
???  minutes = checkTime(minutes);
???  seconds = checkTime(seconds);

???  if (days >= 0 || hours >= 0 || minutes >= 0 || seconds >= 0)
???????????txt.html(days + "天" + hours + "小时" + minutes + "分" + seconds + "秒");
???  if (days <= 0 && hours <= 0 && minutes <= 0 && seconds <= 0) {
???????  window.clearInterval(_ordertimer);
???????  _ordertimer = null;
???  }
??? }

??? function checkTime(i) { //将0-9的数字前面加上0，例1变为01
???  if (i < 10) {
???  i = "0" + i;
???  }
???  return i;
??? }
})