关于倒计时

在项目中遇到一个需求，需要对一个活动进行倒计时，每周三次结算时间，分别为周一周三周五的晚上十一点，

var NowDate = RM.NetMgr.getServerTime()*1000;
        var secondNum = 0;
        var strtime = '1970-01-05 00:00:00:000';
        var date = new Date(strtime.replace(/-/g, '/'));
        var time1 = (NowDate - Date.parse(date))%(7*86400000);
        var week1 = 82800000;
        var week3 = 255600000;
        var week5 = 428400000;
        if(time1 < 82800000){
            secondNum = 82800000 - time1;
        }else if(time1 > 82800000 && time1 < 255600000){
            secondNum = 255600000 - time1;
        }else if(time1 > 255600000 && time1 < 428400000){
            secondNum = 428400000 - time1;
        }else if(time1 > 428400000){
            secondNum = 82800000+604800000 - time1;
        }
        this.lab_timer.text = this.getTimer(secondNum/1000);