javascript 倒计时

// 倒计时

var fnTimeCountDown = function (time) {

    var time = new Date(time).getTime() - new Date().getTime(), // 倒计时时间转变为毫秒数

        days, hours, min, sec, temp;



    if (time <= 0) {

        return null;

    }



    days = Math.floor(time / (24*3600*1000));



    temp = time % (24*3600*1000); // 不够天的转换成小时

    hours = Math.floor(temp / (3600*1000));



    temp = temp % (3600*1000);  // 剩余的分钟数

    min = Math.floor(temp / (60*1000));



    temp = temp % (60*1000);

    sec = Math.floor(temp / (1000));



    // 格式化："05"

    var zero = function (n) {

        var n = parseInt(n, 10);

        if (n > 0) {

            if (n <= 9) {

                n = "0" + n;

            }

            return n;

        } else {

            return "00";

        }

    };



    return {

        days: days,

        hours: zero(hours),

        min: zero(min),

        sec: zero(sec)

    };

};



var future = "2014/01/01 00:00", 

    countobj = null,

    timer = null,

    countdown = function (time, callback) {

        // 倒计时数据对象：countobj

        countobj = fnTimeCountDown(time);

        callback && callback(countobj);



        if (countobj) {

            timer = setTimeout(function () {

                countdown(time, callback);

            }, 1000);

        } else {

            // 倒计时结束

            clearTimeout(timer);

        }

    };



setTimeout(function () {

    countdown(future, function (obj) {

    

        if (obj) {

            // 倒计时应用

            console.log(obj);

        } else {

            // 倒计时结束

            console.log("countdown over!");

        }

    });

}, 0);