def add_months(year, months, offset):
    """
    Add a number of months to the passed in year and month, returning
    a tuple of (year, month)
    """
    months = months - 1  # 0 index months coming in
    nextmonths = months + offset
    months_offset = nextmonths % 12 + 1  # 1 index it going out
    years_offset = nextmonths // 12
    return (year + years_offset, months_offset)