倒计时计算-优快云博客

本文链接：https://blog.youkuaiyun.com/my_prince/article/details/118192461

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        div {
            margin: 200px;
        }
        
        span {
            display: inline-block;
            width: 40px;
            height: 40px;
            background-color: #333;
            font-size: 20px;
            color: #fff;
            text-align: center;
            line-height: 40px;
        }
    </style>
</head>

<body>
    <div>
        <span class="d">0</span>
        <span class="h">1</span>
        <span class="m">2</span>
        <span class="s">3</span>
    </div>
    <script>
        var date = document.querySelector('.d')
        var hour = document.querySelector('.h');
        var minute = document.querySelector('.m');
        var second = document.querySelector('.s');
        var time = +new Date('2021/7/1 18:00:00'); // 返回的是用户输入时间总的毫秒数
        countDown();
        setInterval(countDown, 1000);

        function countDown() {
            var nowTime = +new Date();
            var t = (time - nowTime) / 1000;
            var d = parseInt(t / 60 / 60 / 24);
            d = d >= 10 ? d : '0' + d;
            date.innerHTML = d;
            var h = parseInt(t / 60 / 60 % 24);
            h = h >= 10 ? h : '0' + h;
            hour.innerHTML = h;
            var m = parseInt(t / 60 % 60);
            m = m >= 10 ? m : '0' + m;
            minute.innerHTML = m;
            var s = parseInt(t % 60);
            s = s >= 10 ? s : '0' + s;
            second.innerHTML = s;
        }
    </script>

</html>

在这里插入图片描述