Somewhere along the way to the release of Deepin 15 somebody edited the Timezone data and removed Adelaide (and possibly others) in some form of rationalisation. Not a good move folks.

When proposing removal of time zone entries such as Adelaide there needs to be a rationalisation other than they look the same as others. Yes, on the face of it Adelaide is +9:30 the same as Darwin +9:30 and for aroud 6 months of the year that is true. Unfortunately the problem comes when we fall into the singular joy of Daylight Saving Time. We have it, Darwin doesn't. Ever.
What this means is that I have to set my Time zome to Lord Howe Island as that is presently the required +10:30.

Adelaide used to be on the list after I pointed out  some years ago how many Time Zones had been left out when the time zone list was just an hourly step list. That didn't take long to fix to an all-encompassing list.

Would the person that took it out please put the list back the way it was? You cant rationalise time zones, they are weird and illogical but they are what we have to work with. Each one is there for a reason and that reason is not always obvious.

For anybody wondering about the Time zones of the world my favourite resource is http://www.timeanddate.com but there are plenty of other places that provide a list.