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<title>js实现倒计时</title>
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<meta name="description" content="网页描述" />
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<style type="text/css"></style>
<script type="text/javascript">
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<body>
<div></div>
</body>
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<script>
//函数的参数为活动的结束日期
var stringTime = '2016-12-22 21:23:10';
function daoji(stringTime){
//获取即时时间的对象
var now = new Date();
//获取结束时间的对象
var end = new Date(stringTime);
//获取即时的时间戳
var nowTimeStamp = now.getTime();
//获取活动结束的时间戳
var endTimeStamp = end.getTime();
//活动剩余秒数，js的时间戳是毫秒级别的
var remainSecond= (endTimeStamp - nowTimeStamp) / 1000;
//剩余的秒数等于days+hours+minutes+seconds
var oneDay = 24*60*60;
var oneHour = 60*60;
var oneMinute = 60;
//剩余的天数
var remainDays = parseInt((remainSecond / oneDay));
//减掉整数的天数，并对剩下的进行小时取整就是剩下的小时
var remainHours = parseInt(((remainSecond - (remainDays*oneDay)) / oneHour));
var Hours = parseInt((remainSecond / oneHour));
//减掉整数的小时，并对剩下的进行分钟取整就是剩下的分钟数
var remainMinutes = parseInt((remainSecond - (Hours*oneHour)) / oneMinute);
//减掉整数的分钟就是剩下的秒数
var Minutes = parseInt(remainSecond / oneMinute);
var remainSeconds = parseInt(remainSecond - (Minutes * oneMinute));
//倒计时开始
var endtime = remainDays + '天'+ remainHours + '小时'+ remainMinutes +'分钟'+ remainSeconds +'秒';
var div1 = document.getElementsByTagName('div')[0];
if(remainDays < 0 || remainHours < 0 || remainMinutes < 0 || remainSeconds < 0){
div1.innerHTML = '活动已经结束';
clearInterval(k);
return;
//判断活动是否到期
}else if(remainDays == 0 && remainHours == 0 && remainMinutes == 0 && remainSeconds == 0){
div1.innerHTML = '活动已经结束';
clearInterval(k);//清除定时器
return;
}
div1.innerHTML = '';
div1.innerHTML = endtime;
}
var k =setInterval("daoji(stringTime)",1000);
</script>
