<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<script type="application/javascript">
window.onload = function () {
var showtime = document.getElementById('showtime');
//实现倒计时逻辑
function daojishi() {
var nowtime = new Date();
var futuretime = new Date(2020,3,30,24,0,0);
//计算两个时间有多少时间，获得的是毫秒需要转换成秒
var betweentime = parseInt((futuretime-nowtime)/1000);
//计算还有多少天
var bday = parseInt(betweentime/86400);
//计算还有多少个小时
var bhour = parseInt((betweentime%86400)/60/60);
//计算还有多少分钟
var bmin = parseInt((betweentime%86400%3600/60));
//计算还有多少秒；
var bsec = (betweentime%86400%3600%60);
var str = '现在距离2020年5月1日还有:'+bday+'小时'+bhour+"天"+bmin+"分钟"
+bsec+'秒';
showtime.innerHTML = str;
}
daojishi();
var timer = setInterval(daojishi,1000);
}
</script>
<style>
.showtime {
font-size: 40px;
color: red;
text-align: center;
margin-top: 300px;
}
</style>
</head>
<body>
<div id="showtime" class="showtime"></div>
</body>
</html>