def getMatch(birthdays):
    """Returns the date object of a birthday that occurs more than once in the birthdays list."""
    if len(birthdays) == len(set(birthdays)):
        return None
    
    for a, birthdayA in enumerate(birthdays):
        for b, birthdayB in enumerate(birthdays[a+1:]):
            if birthdayA == birthdayB:
                return birthdayA