# validDate
#
# This function is given integer month day and year. It returns a string, 
# which is either the empty string or a message indicating that
# either the month, day or year is out of range.

def validDate(m,d,y):
	maxDay = [0,31,28,31,30,31,30,31,31,30,31,30,31]
	errorMsg = ""

	if y%400 == 0 or y%100>0 and y%4==0: # this is a leapyear
		if m == 2:
			maxDay[2] = 29
	
	if m < 1 or m > 12:
		errorMsg = "Month out of range"
	else:
		upper = maxDay[m]
		if d<1 or d >upper:
			errorMsg = "Day out of range"
		else:
			if y < 1600 or y > 2200:
				errorMsg = "Year out of range"

	return errorMsg


# testValidDate
#
# This is a test driver to allow repeated testing of the validDate
# function. It allows the user to enter dates, and for each date
# calls validDate. It reports the value validDate returned
# before entering the next date.

def testValidDate():
	month = input("Enter a month(1-12), or 0 to quit: ")

	while month != 0:
		day = input("Enter the day: ")
		year =input("Enter the year: ") 

		message = validDate(month,day,year)

		if message == "":
			print "Date is valid"
		else:
			print message

		month = input("Enter a month(1-12), or 0 to quit: ")

testValidDate()