def cast_position_and_time(cast):
    """Retrieve ONC cast average longitude, latitude and minimum time.

    :arg cast: the ONC cast
    :type cast: a single group of pandas grouby object

    :returns: lat, lon, date
    """

    lon = cast['Longitude Corrected (deg)'].mean()
    lat = cast['Latitude Corrected (deg)'].mean()
    date = cast['day'].min()

    return lat, lon, date