js 正计时和倒计时

showTimeIncrease(){//正计时
    var self = this;
    let count=0;
    self.handle1 =  setInterval(() => {
        var hour = 0, minute = 0, second = 0;
        hour=parseInt(count/60/60);
        minute=parseInt(count/60%60);
        second=parseInt(count%60);
        this.html=self.toDouble(hour)+":"+self.toDouble(minute)+":"+self.toDouble(second);
        count++;
    },1000);

toDouble(num){
    if(num < 10){
        return '0'+ num;
    }else{
        return '' + num;
    }
}

remainingTime(years){//倒计时
    var self = this;
    var dateFinal = new Date(years);  //设置倒计时到达时间
    var dateNow = new Date();  //获取系统当前时间
    var dateSub = dateFinal - dateNow;  //计算差值，单位毫秒
    self.timeHtml  =  '00天00小时00分钟';
    if(dateSub<=0){
        clearInterval(self.intervalDelete);
        return;
    }
    var day = hour = minute = second = dayBase = hourBase = minuteBase = secondBase = 0;  //初始化各个数值
    dayBase = 24 * 60 * 60 * 1000;  //计算天数的基数，单位毫秒。1天等于24*60*60*1000毫秒
    hourBase = 60 * 60 * 1000;  //计算小时的基数，单位毫秒。1小时等于60*60*1000毫秒
    minuteBase = 60 * 1000;  //计算分钟的基数，单位毫秒。1分钟等于60*1000毫秒
    secondBase = 1000;  //计算秒钟的基数，单位毫秒。1秒钟等于1000毫秒
    day = Math.floor(dateSub / dayBase);  //计算天数，并取下限值。如 5.9天 = 5天
    hour = Math.floor(dateSub % dayBase / hourBase);  //计算小时，并取下限值。如 20.59小时 = 20小时
    minute = Math.floor(dateSub % dayBase % hourBase / minuteBase);  //计算分钟，并取下限值。如 20.59分钟 = 20分钟
    //当天数小于等于0时，就不用显示
    if(day <= 0){
        self. timeHtml = self.toDouble(hour) + '小时' +self.toDouble(minute) + '分钟';
    }else{
        self.timeHtml = day + '天' + self.toDouble(hour) + '小时' + self.toDouble(minute) + '分钟';
    }

}