Takes a date from the SWS response object
    and attempts to parse it using one of the several
    datetime formats used by the SWS
    :param date_string:
    :return: date object

def parse_sws_date(date_string):
    """
    Takes a date from the SWS response object
    and attempts to parse it using one of the several
    datetime formats used by the SWS
    :param date_string:
    :return: date object
    """
    if date_string is None:
        return None
    date_formats = ["%m/%d/%Y", "%Y-%m-%d", "%Y%m%d"]
    datetime_obj = None
    for fmt in date_formats:
        try:
            datetime_obj = datetime.strptime(date_string, fmt)
        except ValueError:
            continue
        break
    if datetime_obj is None:
        raise ValueError("Unknown SWS date format")
    return datetime_obj