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

        internal int CheckYearMonthRange(int year, int month, int era) {
            year = CheckYearRange(year, era);

            if (month == 13)
            {
                //Reject if there is no leap month this year
                if (GetYearInfo(year , LeapMonth) == 0)
                    throw new ArgumentOutOfRangeException("month", Environment.GetResourceString("ArgumentOutOfRange_Month"));
            }

            if (month < 1 || month > 13) {
                throw new ArgumentOutOfRangeException("month", Environment.GetResourceString("ArgumentOutOfRange_Month"));
            }
            return year;
        }