基于JavaScript实现HTML页面精确到秒的倒计时功能

 <!doctype html> 
<html> 
<head> 
<meta charset="utf-8"> 

</head> 

<body> 

<DIV id="CountMsg" class="HotDate"> 
<span id="t_d">00天</span> 
<span id="t_h">00时</span> 
<span id="t_m">00分</span> 
<span id="t_s">00秒</span> 
</DIV> 
<script type="text/javascript"> 
function getRTime(){ 
var EndTime= new Date('2014/10/23 10:00:00'); //截止时间 
var NowTime = new Date(); 
var t =EndTime.getTime() - NowTime.getTime(); 
/*var d=Math.floor(t/1000/60/60/24); 
t-=d*(1000*60*60*24); 
var h=Math.floor(t/1000/60/60); 
t-=h*60*60*1000; 
var m=Math.floor(t/1000/60); 
t-=m*60*1000; 
var s=Math.floor(t/1000);*/ 

var d=Math.floor(t/1000/60/60/24); 
var h=Math.floor(t/1000/60/60%24); 
var m=Math.floor(t/1000/60%60); 
var s=Math.floor(t/1000%60); 

document.getElementById("t_d").innerHTML = d + "天"; 
document.getElementById("t_h").innerHTML = h + "时"; 
document.getElementById("t_m").innerHTML = m + "分"; 
document.getElementById("t_s").innerHTML = s + "秒"; 
} 
setInterval(getRTime,1000); 
</script> 
</body> 
</html>