def bump_down(month, year):
    """
    bump is a utility function that takes a given month
    and year and returns the next month and year.  For
    example bump(1, 2014) would return (2, 2014) while
    bump(12, 2013) would return (1, 2014).

    @param month the month to be bumped
    @param year the year to be bumped

    @return a tuple with the next month and year in that order
    """
    month -= 1
    if month == 0:
        year -= 1
        month = 12
    return month, year
