比较全的JavaScript倒计时脚本

JavaScript倒计时在Web中用得非常广泛，比如常见的团购啊、还有什么值得期待的事情，都可以用到倒计时。现在举了四个例子，比如时间长的倒计时，小时倒计时，最简的倒计时，还有秒表等等，应该可以满足大部分需求。

1. 比较长时间的倒计时

<script type="text/javascript">   
startclock();
var timerID = null;   
var timerRunning = false;   
function showtime() {   
	Today = new Date();
	var year = Today.getFullYear();
	document.getElementById("next_yeat").innerHTML = year + 1;
	var NowHour = Today.getHours();   
	var NowMinute = Today.getMinutes();   
	var NowMonth = Today.getMonth();   
	var NowDate = Today.getDate();   
	var NowYear = Today.getYear();   
	var NowSecond = Today.getSeconds();   
	if (NowYear <2000)   
	NowYear=1900+NowYear;   
	Today = null;   
	Hourleft = 23 - NowHour   
	Minuteleft = 59 - NowMinute   
	Secondleft = 59 - NowSecond   
	Yearleft = year - NowYear   
	Monthleft = 12 - NowMonth - 1 
	Dateleft = 31 - NowDate   
	if (Secondleft<0)   
	{   
		Secondleft=60+Secondleft;   
		Minuteleft=Minuteleft-1;   
	}   
	if (Minuteleft<0)   
	{    
		Minuteleft=60+Minuteleft;   
		Hourleft=Hourleft-1;   
	}   
	if (Hourleft<0)   
	{   
		Hourleft=24+Hourleft;   
		Dateleft=Dateleft-1;   
	}   
	if (Dateleft<0)   
	{   
		Dateleft=31+Dateleft;   
		Monthleft=Monthleft-1;   
	}   
	if (Monthleft<0)   
	{   
		Monthleft=12+Monthleft;   
		Yearleft=Yearleft-1;   
	}   
	Temp=Yearleft+'年, '+Monthleft+'月, '+Dateleft+'天, '+Hourleft+'小时, '+Minuteleft+'分, '+Secondleft+'秒';
	document.form1.left.value=Temp;   
	timerID = setTimeout("showtime()",1000);   
	timerRunning = true;   
}   
var timerID = null;   
var timerRunning = false;   
function stopclock () {   
	if(timerRunning)   
	clearTimeout(timerID);   
	timerRunning = false;   
}   
function startclock () {   
	stopclock();   
	showtime();   
}   
// -->   
</script>   

　　

2. 小时倒计时（短时间倒计时）

<script type="text/javascript">   
<!--   
//一个小时，按秒计算，可以自己调整时间
var maxtime = 60*60 
function CountDown()
{   
	if(maxtime>=0)
	{   
		minutes = Math.floor(maxtime/60);   
		seconds = Math.floor(maxtime%60);   
		msg = "距离结束还有 "+minutes+" 分 "+seconds+" 秒";   
		document.all["timer"].innerHTML=msg;   
		if(maxtime == 5*60) alert('注意，还有5分钟!');   
		--maxtime;   
	}   
	else
	{   
		clearInterval(timer);   
		alert("时间到，结束!");   
	}   
}   
timer = setInterval("CountDown()",1000);   
//-->   
</script>

　　转载：原文来自http://www.nowamagic.net/librarys/veda/detail/421