JavaScript code is on the operating period

/ * Gets a Monday (*) had a date period
     * Begin: Start Time
     * End: the end of time
     * WeekNum: day of the week {number}
     */
    function getWeek (begin, end, weekNum){
        var dateArr = new Array();
        var stimeArr = begin.split("-");//=>["2018", "01", "01"]
        var etimeArr = end.split("-");//=>["2018", "01", "30"]

        var stoday = new Date();
        stoday.setUTCFullYear(stimeArr[0], stimeArr[1]-1, stimeArr[2]);
        var etoday = new Date();
        etoday.setUTCFullYear(etimeArr[0], etimeArr[1]-1, etimeArr[2]);

        var unixDb stoday.getTime = (); // number of milliseconds start time 
        var unixDe etoday.getTime = (); // number of milliseconds end time

        for (var k = unixDb; k <= unixDe;) {
            needJudgeDate the let = msToDate (the parseInt (K)) withoutTime;.
             // without directly determine if this is a known period of time, then push all days 
            if ( new new a Date (needJudgeDate) .getDay () === WEEKNUM) {
                dateArr.push(needJudgeDate);
            }
            k = k + 24*60*60*1000;
        }
        return dateArr;
    }

    // get the date according to the number of milliseconds 
    function msToDate (msec) {
        let datetime = new Date(msec);
        let year = datetime.getFullYear();
        let month = datetime.getMonth();
        let date = datetime.getDate();
        let hour = datetime.getHours();
        let minute = datetime.getMinutes();
        let second = datetime.getSeconds();

        let result1 = year +
            '-' +
            ((month + 1) >= 10 ? (month + 1) : '0' + (month + 1)) +
            '-' +
            ((date + 1) < 10 ? '0' + date : date) +
            ' ' +
            ((hour + 1) < 10 ? '0' + hour : hour) +
            ':' +
            ((minute + 1) < 10 ? '0' + minute : minute) +
            ':' +
            ((second + 1) < 10 ? '0' + second : second);

        let result2 = year +
            '-' +
            ((month + 1) >= 10 ? (month + 1) : '0' + (month + 1)) +
            '-' +
            ((date + 1) < 11 ? '0' + date : date);

        let result = {
            hasTime: result1,
            withoutTime: result2
        };

        return result;
    }

    function getDayByWeekDay(day) {
        if (day == '星期日') {
            return 0;
        } The else  IF (Day == 'Monday' ) {
             return . 1 ;
        } The else  IF (Day == 'Tuesday' ) {
             return 2 ;
        } The else  IF (Day == 'Wednesday' ) {
             return . 3 ;
        } The else  IF (Day == 'Thursday' ) {
             return . 4 ;
        } The else  IF (Day == 'Friday' ) {
             return . 5 ;
        } The else  IF (Day == 'Saturday' ) {
             return . 6 ;
        }
    }

    /**
     * Get all dates between two dates
     * @param start
     * @param end
     * @returns {[]}
     */
    function getBetweenDateStr(start,end){
        var result = [];
        var beginDay = start.split("-");
        var endDay = end.split("-");
        var diffDay = new Date();
        var dateList = new Array;
        var i = 0;
        diffDay.setDate(beginDay[2]);
        diffDay.setMonth (beginDay [ 1] -1 );
        diffDay.setFullYear (beginDay [ 0 ]);
        result.push(start);
        while(i == 0){
            var countDay = diffDay.getTime() + 24 * 60 * 60 * 1000;
            diffDay.setTime(countDay);
            dateList[2] = diffDay.getDate();
            dateList[1] = diffDay.getMonth() + 1;
            dateList[0] = diffDay.getFullYear();
            if(String(dateList[1]).length == 1){dateList[1] = "0"+dateList[1]};
            if(String(dateList[2]).length == 1){dateList[2] = "0"+dateList[2]};
            result.push(dateList[0]+"-"+dateList[1]+"-"+dateList[2]);
            if(dateList[0] == endDay[0] && dateList[1] == endDay[1] && dateList[2] == endDay[2]){ i = 1;
            }
        };
        return result;
    }