JS 倒计时

var countDownTime = {

    init: function(a, b, c, d, e) {

        this.t = a, this.d = b, this.h = c, this.m = d, this.s = e

    },

    start: function() {

        var a = this;

        setInterval(a.timer, 1e3)

    },

    timer: function(a) {

        var b, c, d, e, f, g, h;

        a = this.countDownTime, b = new Date, c = new Date(a.t), d = c.getTime() - b.getTime(), e = Math.floor(a.formatTime(d, "day")), f = Math.floor(a.formatTime(d, "hours")), g = Math.floor(a.formatTime(d, "minutes")), h = Math.floor(a.formatTime(d, "seconds")), a.d && (a.d.innerText = a.formatNumber(e)), a.h && (a.h.innerText = a.formatNumber(f)), a.m && (a.m.innerText = a.formatNumber(g)), a.s && (a.s.innerText = a.formatNumber(h))

    },

    formatNumber: function(a) {

        if(a<=0){a=0}

        return a = a.toString(), a[1] ? a : "0" + a

    },

    formatTime: function(a, b) {

        switch (b) {

            case "day":

                return a / 1e3 / 60 / 60 / 24;

            case "hours":

                return a / 1e3 / 60 / 60 % 24;

            case "minutes":

                return a / 1e3 / 60 % 60;

            case "seconds":

                return a / 1e3 % 60

        }

    }

};

 

 

<script>

        var day = document.getElementById('day');

        var hours = document.getElementById('hours');

        var minutes = document.getElementById('minutes');

        var seconds = document.getElementById('seconds');

        // 日 时 分 秒的dom对象

        countDownTime.init('2030/8/23 20:00:00', day, hours, minutes, seconds);

        countDownTime.start();

    </script>