(function (){    var jtimer = function() {        // init        if(arguments.length >= 1) {            this.setEndTime(arguments[0]);        }        if(arguments.length >= 2) {            this.setGenerateCallBack(arguments[1]);        }    };    jtimer.prototype.setEndTime = function () {        if(arguments.length == 1) {            this.endTime = arguments[0]; // Date        }    }    jtimer.prototype.getMillisecond = function () {        return this.endTime.getTime() - new Date().getTime();    };    jtimer.prototype.setGenerateCallBack = function (callback) {        if(typeof callback == "undefined") return;        this.generateCallBack = callback;    }    jtimer.prototype.generate = function () {        if(typeof this.generateCallBack == "undefined") return;        var ms = this.getMillisecond();        this.generateCallBack(            Math.floor(ms/(1000 * 60 * 60 * 24)),            Math.floor(ms/(1000*60*60)) % 24,            Math.floor(ms/(1000*60)) % 60,            Math.floor(ms/1000) % 60        );    };    jtimer.prototype.start = function () {        var delay = 1000;        if(arguments.length == 1) {            delay = arguments[0];        }        _this = this; // for closure        this.interval = window.setInterval(            function() {                _this.generate();            }, delay);    }    jtimer.prototype.stop = function () {        if(typeof this.interval == "undefined") return;        window.clearInterval(this.interval);        this.interval = undefined;    }    window.jtimer = jtimer;})();var jt = new jtimer(new Date("6/27/2016"), function (day, hour, min, sec) {    console.log(day + "," + hour + "," + min + "," + sec);});jt.start(1000);