jQuery每日秒杀商品倒计时

html & js：

<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>jQuery每日秒杀倒计时</title>
<link rel="stylesheet" href="css/zzsc.css">
</head>
<body>
<div class="se-kl">
 <div class="se-cn">倒计时</div>
 <div class="se-en">COUNT DOWN</div>
 <i class="se-io"></i>
 <div class="se-info">距离结束还剩</div>
 <div class="se-count">
  <div class="se-day"></div>
  <div class="se-hour"><span class="se-txt">00</span></div>
  <div class="se-min"><span class="se-txt">00</span></div>
  <div class="se-sec"><span class="se-txt">00</span></div>
 </div>
</div>
<script src="js/jquery.min.js"></script>  <!-- 依赖条件1 -->
<script type="text/javascript">
 $(document).ready(function () {
  var oDate = new Date();
  var nowTime = oDate.getTime(); //现在的毫秒数
  oDate.setDate(oDate.getDate() + 1); // 设定截止时间为第二天
  var targetDate = new Date(oDate.toLocaleDateString());
  run(targetDate);
 });

 function run(enddate) {
  getDate(enddate);
  setInterval("getDate('" + enddate + "')", 500);
 }

 function getDate(enddate) {
  var oDate = new Date(); //获取日期对象

  var nowTime = oDate.getTime(); //现在的毫秒数
  var enddate = new Date(enddate);
  var targetTime = enddate.getTime(); // 截止时间的毫秒数
  var second = Math.floor((targetTime - nowTime) / 1000); //截止时间距离现在的秒数

  var day = Math.floor(second / 24 * 60 * 60); //整数部分代表的是天；一天有24*60*60=86400秒 ；
  second = second % 86400; //余数代表剩下的秒数；
  var hour = Math.floor(second / 3600); //整数部分代表小时；
  second %= 3600; //余数代表 剩下的秒数；
  var minute = Math.floor(second / 60);
  second %= 60;
  var spanH = $('.se-txt')[0];
  var spanM = $('.se-txt')[1];
  var spanS = $('.se-txt')[2];

  spanH.innerHTML = tow(hour);
  spanM.innerHTML = tow(minute);
  spanS.innerHTML = tow(second);
 }

 function tow(n) {
  return n >= 0 && n < 10 ? '0' + n : '' + n;
 }
</script>
</body>
</html>

css：

(zzsc.cs)

* {
    margin: 0;
    padding: 0;
}

.se-kl {
    width: 190px;
    height: 275px;
    background-color: #e83632;
    margin: 100px auto;
    position: relative;
}

.se-cn {
    position: absolute;
    top: 42px;
    left: 0;
    width: 100%;
    text-align: center;
    font-size: 34px;
    color: #fff;
}

.se-en {
    position: absolute;
    top: 90px;
    left: 0;
    width: 100%;
    text-align: center;
    font-size: 20px;
    color: rgba(255, 255, 255, 0.5);
}

.se-io {
    width: 20px;
    height: 33px;
    position: absolute;
    background: url(../imgs/seckill.png) no-repeat;
    background-position: -32.5px 0;
    background-size: 52.5px 40px;
    left: 85px;
    top: 126px;
    display: block;
}

.se-info {
    position: absolute;
    top: 170px;
    text-align: center;
    width: 100%;
    font-size: 16px;
    color: #fff;
}

.se-count {
    position: absolute;
    top: 212px;
    left: 30px;
    height: 40px;
}

.se-day {
    display: none;
}

.se-hour,
.se-min,
.se-sec {
    position: relative;
    background-color: #2f3430;
    width: 40px;
    height: 40px;
    float: left;
    text-align: center;
    line-height: 40px;
    margin-right: 5px;
}

.se-txt {
    font-size: 20px;
    font-weight: bold;
    color: #fff;
}

.se-txt:before {
    content: "";
    display: block;
    position: absolute;
    top: 50%;
    left: 0;
    width: 100%;
    height: 1px;
    background-color: #e83632;
}

示例图1：

注：本程序依赖于jquery库，请自行下载并选择合适路径或使用远程cdn地址：https://cdn.bootcss.com/jquery/3.4.1/jquery.js