Get Weeks In Month

    getWeeksInMonth = function (month, year){
        var weeks=[],
            firstDate=new Date(year, month, 1),
            lastDate=new Date(year, month+1, 0),
            numDays= lastDate.getDate();

        var start=1;
        var end=7-firstDate.getDay();
        var weekday = new Array(7);
        weekday[0]=  "Sun";
        weekday[1] = "Mon";
        weekday[2] = "Tue";
        weekday[3] = "Wed";
        weekday[4] = "Thu";
        weekday[5] = "Fri";
        weekday[6] = "Sat";

        while(start<=numDays){
            var dayNames = [];
            for (i = start; i <= end; i++) {
                var day = new Date(year, month, i).getDay();
                dayNames.push(weekday[day]);
            }
            weeks.push(dayNames);
            start = end + 1;
            end = end + 7;
            if(end>numDays)
                end=numDays;
        }
         return weeks;
    },