def parse_timezone(tz=None):
    """
    Gets a timezone object from a timezone string. Includes some abbreviations
    useful for Scott. If the input is not a string, it is returned as is.
    """
    abbreviations = {'CA': 'US/Pacific', 'DK': 'Europe/Copenhagen'}
    if tz is not None:
        import pytz
    if tz in abbreviations:
        return pytz.timezone(abbreviations[tz])
    elif type(tz) is str:
        return pytz.timezone(tz)
    return tz
