1 <!DOCTYPE html>
2 <html>
3 <head lang="en">
4 <meta charset="UTF-8">
5 <title>倒计时</title>
6 </head>
7 <body>
8
9 </body>
10 <script type="text/javascript">
11 function timer(targetTime){
12 var date = new Date();
13 var dateTarget = new Date(targetTime);
14 var timeTarget = dateTarget.getTime();
15 var time = date.getTime();
16 if(timeTarget<time){
17 return "目标时间不能小于当前时间";
18 }
19 var time_difference = timeTarget-time;
20 var hour_point = time_difference/(1000*60*60);
21 var hour = Math.floor(hour_point);
22 var hour_difference = hour_point-hour;
23 var minute_point = hour_difference*60;
24 var minute = Math.floor(minute_point);
25 var minute_difference = minute_point - minute;
26 var second = Math.floor(minute_difference*60);
27 if(Number(hour)==0 && Number(minute)==0 && Number(second)==0){
28 return "时间到";
29 }
30 var timeStr = "还有 "+addZero(hour)+"小时 "+addZero(minute)+"分钟 "+addZero(second)+"秒 到时";
31 return timeStr;
32 };
33
34 var timeFun = setInterval(function(){
35 var time_ = timer("2017/3/31 22:25:00");
36
37 document.body.innerHTML = time_;
38
39 if(time_ == "时间到" || time_=="目标时间不能小于当前时间"){
40 clearInterval(timeFun);
41 }
42
43 },1000);
44
45 function addZero(time){
46 return time<0?"0"+time:time;
47 }
48
49 </script>
50 </html>
