private static int daysInMonth(int m, int y) {
		if (m == 4 || m == 6 || m == 9 || m == 11)
			return 30;
		if (m == 2) {
			if (y % 4 == 0) // 2000 divisible by 400, only century
				return 29;
			return 28;
		}
		return 31;
	}