<!DOCTYPE html>
<html lang="zh-cn">
<head>
<meta charset="UTF-8">
<title>倒计时精确到毫秒</title>
<style>
#timer {
height:50px;
width:100%;
text-align:center;
line-height:50px;
background:black;
color:white;
}
</style>
<script>
function countDown(dd) {
var t = new Date(dd),
n = new Date().getTime(),
c = t - n;
// 结束执行
if (c <= 0) {
clearInterval(window['timer']);
return;
}
d = parseInt(c / 1000 / 60 / 60 / 24),
h = parseInt(c / 1000 / 60 / 60 - (24 * d)),
m = parseInt(c / 1000 / 60 - (24 * 60 * d) - (60 * h)),
s = parseInt(c / 1000 - (24 * 60 * 60 * d) - (60 * 60 * h) - (60 * m));
hm = Math.floor((c - (24 * 60 * 60 * 1000 * d) - (60 * 60 * 1000 * h) - (60 * 1000 * m) - (s * 1000)) / 10);
if (hm < 10) {hm = "0" + hm;}
if (s < 10) {s = "0" + s;}
if (m < 10) {m = "0" + m;}
if (h < 10) {h = "0" + h;}
document.getElementById('timer').innerHTML = '距离2118年10月1日还有：' + d + '天' + h + '小时' + m + '分钟' + s + '秒' + hm + '毫秒';
}
(function() {
window['timer'] = setInterval(function() {
countDown('2118/10/1 00:00:00:00');
}, 50);
})();
</script>
</head>
<body>
<div id="timer"></div>
</body>
</html>
