<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>元旦倒计时</title>
<style type="text/css">
#msg{
text-align: center;
font-size: 130px;
}
#timer{
font-size: 130px;
color: red;
}
</style>
<script type="text/javascript">
function showTime(){
var currentTime=new Date();
var endTime=new Date("2015/2/13");
var remainTime=endTime.getTime()-currentTime.getTime();
// 1天=24小时 1小时=60分钟 1分钟=60秒 1秒=1000毫秒
var day=Math.floor(remainTime/(24*60*60*1000));
var hour=Math.floor((remainTime-day*24*60*60*1000)/(60*60*1000));
var minute=Math.floor((remainTime-day*24*60*60*1000-hour*60*60*1000)/(60*1000));
var second=Math.floor((remainTime-day*24*60*60*1000-hour*60*60*1000-minute*60*1000)/(1000));
if(remainTime<0){
document.getElementById("msg").innerHTML="元旦已经结束！";
}else{
var time=day+"天 "+hour+"时"+minute+"分"+second+"秒！";
document.getElementById("timer").innerHTML=time;
}
}
setInterval("showTime()",1000);
</script>
</head>
<body>
<div id="msg">距离网博放假还有：<br/><span id="timer"></span><br/>一定要Holder住!!!!</div>
</body>
</html>JavaScript - 倒计时实例（元旦、国庆、中秋倒计时）
原文：http://blog.csdn.net/wangzi11322/article/details/45287949