I have downloaded the latest geonames timezone data dump and imported it to my MySQL database. For the timezone id 'Australia/Melbourne' I believe the gmt offset and dst offset has been reversed. The gmt offset should return 10 and it returns 11, the dst offset should return 11 but it returns 10. Thanks in advance.
The naming of the fields is not very appropriate. The fields in reality refer to 1. of Jan and 1. of July.
We consider the fields obsolete as they are not very useful. It was a mistake to have them included at all.