System.Globalization.EastAsianLunisolarCalendar.InternalGetDaysInMonth C# (CSharp) Method

        internal int InternalGetDaysInMonth(int year, int month) {
            int nDays;
            int mask;        // mask for extracting bits

            mask = 0x8000;
            // convert the lunar day into a lunar month/date
            mask >>= (month-1);
            if ((GetYearInfo(year, nDaysPerMonth) & mask)== 0)
                nDays = 29;
            else
                nDays = 30;
            return nDays;
        }