<!DOCTYPE html>
<html>
<head>
<title></title>
</head>
<style type="text/css">
</style>
<body>
<div id="day"></div>
<div id="hous"></div>
<div id="mit"></div>
<div id="mao"></div>
</body>
</html>
<script type="text/javascript">
var day=document.getElementById('day');
var hous=document.getElementById('hous');
var mit=document.getElementById('mit');
var mao=document.getElementById('mao');
var time=setInterval(function (argument) {
// body...
var date=new Date();
var target=new Date('2019-07-20 00:00');
var num=(target-date)/1000;
var d=parseInt(num/60/60/24);
var h=parseInt(num/60/60%24);
var m=parseInt(num/60%60);
var s=parseInt(num%60);
day.innerText=d;
hous.innerText=h;
mit.innerText=m;
mao.innerText=s;
},1000);
</script>
