JavaScript-倒计时效果

 1 DOCTYPE html>
 2 html lang="en">
 3 head>
 4     meta charset="UTF-8">
 5     meta name="viewport" content="width=device-width, initial-scale=1.0">
 6     meta http-equiv="X-UA-Compatible" content="ie=edge">
 7     title>倒计时title>
 8     style>.time-item {
 9         width: 450px;
10         height: 45px;
11         margin: 0 auto;
12       }
13 
14       .time-item strong {
15           background: orange;
16           color: #fff;
17           line-height: 49px;
18           font-size: 36px;
19           font-family: Arial;
20           padding: 0 10px;
21           margin-right: 10px;
22           border-radius: 5px;
23           box-shadow: 1px 1px 3px rgba(0, 0, 0, 0.2);
24       }
25 
26       .time-item > span {
27           float: left;
28           line-height: 49px;
29           color: orange;
30           font-size: 32px;
31           margin: 0 10px;
32           font-family: Arial, Helvetica, sans-serif;
33       }
34       .title {
35         width: 260px;
36         height: 50px;
37         margin:200px auto 50px auto;
38       }style>
39 head>
40 body onload="leftTimer()">
41     h1 class="title">距离光棍节，还有h1>
42 
43   div class="time-item" >
44     span>span id="day">span>天span>
45     strong>span id="hour">span>时strong>
46     strong>span id="minute">span>分strong>
47     strong>span id="second">span>秒strong>
48   div>
49   script type="text/javascript">
50       function leftTimer(year,month,day,hour,minute,second){
51 
52           // 参数monthIndex 是从“0”开始计算的，这就意味着一月份为“0”，十二月份为“11”
53           //以一个函数的形式来调用 Date 对象（即不使用 new 操作符）会返回一个代表当前日期和时间的字符串。
54           var leftTime = (new Date(year,month-1,day,hour,minute,second)) - (new Date()); //计算剩余的毫秒数
55 
56           //parseInt解析一个字符串，返回整数
57           var days = parseInt(leftTime / 1000 / 60 / 60 / 24 , 10);
58           var hours = parseInt(leftTime / 1000 / 60 / 60 % 24 , 10);
59           var minutes = parseInt(leftTime / 1000 / 60 % 60, 10);
60           var seconds = parseInt(leftTime / 1000 % 60, 10);
61 
62           //不足10的前面加上0
63           days = checkTime(days);
64           hours = checkTime(hours);
65           minutes = checkTime(minutes);
66           seconds = checkTime(seconds);
67 
68           // 设置计时器
69           setInterval("leftTimer(2019,11,11,11,11,11)",1000);
70 
71           //将时间加到文中
72           document.getElementById(‘day‘).innerHTML = days;
73           document.getElementById(‘hour‘).innerHTML = hours;
74           document.getElementById(‘minute‘).innerHTML = minutes;
75           document.getElementById(‘second‘).innerHTML = seconds;
76       }
77       function checkTime(i){ //将0-9的数字前面加上0
78           if(i10)
79           {
80               i = "0" + i;
81           }
82           return i;
83       }
84 
85   script>
86 body>
87 html>