代码
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<div id="box"></div>
<script>
/*
未来时间 - 现在时间 = 等待时间 时间戳(ms)
*/
setInterval(auto,1000);
function auto(){
var currentTime = new Date(); // 当前时间
var targetTime = new Date(2020,9,1,0,0,0); // 未来时间
var waitTime = (targetTime - currentTime)/1000; // 秒数
// console.log(waitTime);
// 一天 24*60*60 = 86400 s
// 一小时 60*60 = 3600 s
// 一分钟 60s
var day = parseInt(waitTime / 86400);
var hours = parseInt((waitTime % 86400)/3600);
var minutes = parseInt((waitTime % 86400)%3600 / 60);
var seconds = parseInt((waitTime % 86400)%3600 % 60);
var box = document.getElementById('box');
box.innerHTML = '距离2020年国庆节还有:' + day + '天' + addZero(hours) +'小时' + addZero(minutes) + '分' + addZero(seconds) + '秒钟';
}
auto();
// 加0封装
function addZero(time) {
return time = time >=10? time:'0'+time
}
</script>
</body>
</html>
效果