js倒计时（可定义截止日期）

1 <div id="times_wrap" class="time_num">
2     距离结束时间：
3     <div class="time_w">
4         <b id="times_d" class="time"> </b>天
5         <b id="times_h" class="time"> </b>时
6         <b id="times_m" class="time"> </b>分
7         <b id="times_s" class="time"> </b>秒
8     </div>
9 </div>

 1 var time_wrap = document.getElementById("times_wrap");
 2     var time_d = document.getElementById("times_d");
 3     var time_h = document.getElementById("times_h");
 4     var time_m = document.getElementById("times_m");
 5     var time_s = document.getElementById("times_s");
 6 
 7     var time_end = new Date("2015/9/30 18:00:00");  // 设定结束时间
 8     time_end = time_end.getTime();
 9 
10     function show_time(){
11         var time_now = new Date();  // 获取当前时间
12         time_now = time_now.getTime();
13         var time_distance = time_end - time_now;  // 结束时间减去当前时间
14         var int_day, int_hour, int_minute, int_second;
15         if(time_distance >= 0){
16             // 天时分秒换算
17             int_day = Math.floor(time_distance/86400000)
18             time_distance -= int_day * 86400000;
19             int_hour = Math.floor(time_distance/3600000)
20             time_distance -= int_hour * 3600000;
21             int_minute = Math.floor(time_distance/60000)
22             time_distance -= int_minute * 60000;
23             int_second = Math.floor(time_distance/1000)
24 
25             // 时分秒为单数时、前面加零站位
26             if(int_hour < 10)
27                 int_hour = "0" + int_hour;
28             if(int_minute < 10)
29                 int_minute = "0" + int_minute;
30             if(int_second < 10)
31                 int_second = "0" + int_second;
32 
33             // 显示时间
34             time_d.innerHTML = int_day;
35             time_h.innerHTML = int_hour;
36             time_m.innerHTML = int_minute;
37             time_s.innerHTML = int_second;
38         }else{
39             time_d.innerHTML = time_d.innerHTML;
40             time_h.innerHTML = time_h.innerHTML;
41             time_m.innerHTML = time_m.innerHTML;
42             time_s.innerHTML = time_s.innerHTML;
43         }
44     };
45     window.setInterval(function(){
46         show_time();
47     }, 1000);