def is_timezone_aware(value):
    """Check if a datetime is time zone aware.

    `is_timezone_aware()` is the inverse of `is_timezone_naive()`.

    :param value: A valid datetime object.
    :type value: datetime.datetime, datetime.time
    :returns: bool -- if the object is time zone aware.

    .. versionadded:: 0.3.0
    """
    assert hasattr(value, 'tzinfo')
    return value.tzinfo is not None and value.tzinfo.utcoffset(value
        ) is not None
