public static int monthLength(int month, int year)
	{
		if (month < 1 || month > 12)
			throw new IllegalArgumentException("Month out of bounds");
		if (year <= 0)
			throw new IllegalArgumentException("Year must be positive.");

		int length = 31;
		if (month == 4 || month == 6 || month == 9 || month == 11)
			length = 30;
		else if (month == 2) {
			if (DU.isLeapYear(year))
				length = 29;
			else
				length = 28;
		}
		return length;
	}