I know I am a long way away from the scene of the action, but from looking at the map this looks about as likely as Eigg, Muck or Canna having different DST rules from the rest of the UK; ie. not very. :-)
My Times Concise Atlas lists Hayman and Lindeman as being on either side of Whitsunday Island. My Britannica Atlas doesn't list either but gives 20.17S 148.59E for Whitsunday. Neither has any trace of Hamilton.
I have actually *been* to Hamilton Island, and a close friend of mine recently had a holiday on Hayman Island. The three islands are probably owned entirely by holiday (that's "vacation" to you North Americans) operators and probably made autonomous decisions as to what time to keep on their properties. I have heard or read more than once that some resort islands off the coast of Queensland chose to keep observing daylight-saving time even after Queensland ceased to. It seems that no only does each state decide independantly if and when to observe daylight saving, but commercially run holiday resorts can also do it their way. And then there's Lord Howe Island (what a disaster!). I have reason to doubt, by the way, that "Holiday Islands" is an officially gazetted name: it's not one I'm familiar with; as far as I'm aware, all these islands are part of the Whitsunday Islands group.
Of my trio of islands, Eigg and Canna are also privately owned (I don't know about Muck). I fail to see why owning land that is bounded by sea rather than land bounded by a more normal fence makes the owners any less subject to the Summer Time Act 1972 than I am. Don't you have laws in Australia? :-) Seriously, should the tz database document legal time, or should it also document other sorts of `custom and practice' time? If the latter I'm sure I can promulgate an Aldie time to be observed on my patch that would break something in the existing code. :-) Another nearby island, Rum (Rhum if you believe the Ordnance Survey) is also owned by a single organisation and is largely given over to research into Red Deer. Maybe I should suggest to Scottish Natural Heritage that their scientific work justifies keeping UTC all year round.
Australia's vying powers-that-be unfortunately have a very childish, ingnorant and it seems almost purely politically motivated approach to daylight saving. ... But I digress...
We have the same thing. People seem reluctant to give up summer time, as shown by popular support in the rest of Europe for changing from September to October, but don't seem to think of demanding an earlier start. At least we are making progress here on the cooperation front, at least until the French upset things by suggesting they would scrap the whole idea. Peter Ilieve peter@aldie.co.uk