javascript 学习笔记（四） 倒计时程序代码

<p> 
<label for="deadline">截止日期</label> 
<input type="text" value="2011-06-11" id="deadline" /> 
<input type="button" value="开始倒计时" onclick="window.setInterval('countDown(\'deadline\')', 1000)" /> 
</p> 
<p id="showTime"></p> 
 
javascript部分代码： 
 代码如下:

function countDown(endDate) { 
var now = new Date(); 
var deadtime = document.getElementById(endDate); 
var deadline = new Date(deadtime.value); 
//本地时间与格林威治标准时间 (GMT) 的分钟差 
var timeDiff = now.getTimezoneOffset(); 
//此处有些不解，如果把分钟差转化成毫秒应该是timeDiff*60*1000，但是这样返回的数据不正确！ 
var leave = Math.abs(deadline.getTime() - now.getTime() + timeDiff*60); 
var minute = 1000 * 60; 
var hour = minute * 60; 
var day = hour * 24; 
var countDay = Math.floor(leave/day); 
//var countHour = Math.floor((leave - day*countDay)/hour); 两种计算思路 
var countHour = Math.floor(leave/hour - countDay*24); 
var countMinute = Math.floor(leave/minute) - countDay*24*60 - countHour*60; 
var countSecond = Math.floor(leave/1000) - countDay*24*60*60 - countHour*60*60 - countMinute*60; 
var outStr = ""; 
if(deadline < now) { 
outStr = "距离"+deadtime.value+"已有"+countDay+"天"+countHour+"小时"+countMinute+"分"+countSecond+"秒"; 
} else { 
outStr = "距离"+deadtime.value+"还差"+countDay+"天"+countHour+"小时"+countMinute+"分"+countSecond+"秒"; 
} 
var showTime = document.getElementById("showTime"); 
showTime.innerHTML = outStr; 
}