def ddmmmyy(arrow_date):
    """Return an Arrow date as a string formatted as lower-cased `ddmmmyy`; e.g. 28feb22.

    :param arrow_date: Date/time to format.
    :type arrow_date: :py:class:`arrow.arrow.Arrow`

    :return: Date formatted as lower-cased `ddmmmyy`.
    :rtype: str
    """
    return arrow_date.format("DDMMMYY").lower()