做了一个显示活动倒计时的功能，方便用到时直接拿来就用
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>与今天之后的某一特定时间的倒计时</title>
</head>
<body>
<div>离结束时间还差<span style="color:red; font-weight:bold;" id="day"></span>天<span style="color:red; font-weight:bold;" id="hour"></span>小时<span style="color:red; font-weight:bold;" id="fen"></span>分<span style="color:red; font-weight:bold;" id="miao"></span>秒</div>
<script>
//getTimeS(86400000);
getTimeS(new Date(2017,6,3,10,40,0) - new Date());//当前时间 与 2017年7月3号10点40分 差值
function getTimeS(newTime){
var timer;
function djs(){
if(newTime <= 0){
clearInterval(timer);
document.getElementById('day').innerHTML = 0;
document.getElementById('hour').innerHTML = 0;
document.getElementById('fen').innerHTML = 0;
document.getElementById('miao').innerHTML = 0;
alert('活动已结束');
return;
}
var newTimeS = newTime / 1000;
var day = 24*60*60;
var hour = 60*60;
var fen = 60;
var newDay = Math.floor(newTimeS / day);
var newHour = Math.floor(newTimeS % day / hour);
var newfen = Math.floor(newTimeS % hour / fen);
var newMiao = Math.floor(newTimeS % fen);
console.log(newDay , newHour , newfen , newMiao);
document.getElementById('day').innerHTML = newDay;
document.getElementById('hour').innerHTML = newHour;
document.getElementById('fen').innerHTML = newfen;
document.getElementById('miao').innerHTML = newMiao;
newTime = newTime - 1000;
}
djs();
timer = setInterval(djs,1000);
}
</script>
</body>
</html>