用Javascript 实现倒计时
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
.time1{
width: 500px;
height: 300px;
background-color: #cccccc;
color: red;
border: 1px solid green;
margin: 100px auto;
}
</style>
</head>
<body>
<div class="time1"></div>
<script>
var div=document.getElementsByClassName("time1")[0];
//定义一个计时器
setInterval(fn,1);
//封装成功方法，每隔固定时间调用一次
function fn() {
//1.获取时间差，将来的时间剪去现在的时间
var futureTime=new Date("2018/09/08 01:00:00");
var nowTime=new Date();
//时间差（毫秒值）=未来时间-当前时间
var sumMS=futureTime.getTime()-nowTime.getTime();
//2.把时间差转化成：天时分秒毫秒
var day=parseInt(sumMS/1000/60/60/24);
var hour=parseInt(sumMS/1000/60/60%24);
var minute=parseInt(sumMS/1000/60%60);
var second=parseInt(sumMS/1000%60);
var ms=parseInt(sumMS%1000);
day=day<10?"0"+day:day;
minute=minute<10?"0"+minute:minute;
hour=hour<10?"0"+hour:hour;
second=second<10?"0"+second:second;
if(ms<10){
ms="00"+ms;
}else if (ms<100){
ms="0"+ms;
}
//3.把天时分秒毫秒整合成字符串后赋值给div的innerHTML
div.innerHTML="距苹果发布会还有："+day+"天"+hour+"小时"+minute+"分"+second+"秒"+ms+"毫秒"
}
</script>
</body>
</html>