You write the time upside down. Ahem. I'm unsure of your question. The military time zones are based on astronomical fundamentals and are set every 15 Degrees of Longitude. The Sun travels 15 Degrees every hour and is the basis for time. They have no connection to civil time zones or locally created variations.
The state of South Australia is UTC + 9:30. There isn't a letter for that. Okay, I guess that explains it but ... why do they have a few 7.5 degree "star" zones? They're in Europe so maybe something to do with WW2. It seems like there should be an India Star as a timezone in one of the US's main allies.
For time (and date) format, I humbly refer you to ISO 8601; scroll down to the Universal Coordinated Time section: https://en.wikipedia.org/wiki/ISO_8601
If it helps, time/date stamps in standard Internet email headers look like this: Mon, 8 Oct 2018 19:07:45 +0000 The offset in hours and minutes from UTC is given by the last field, with +0000 meaning UTC. I always write dates as "8 Oct 2018" to eliminate the ambiguity of expressions like 10/8/2018. Is that October 8 or August 10? One of my pet peeves is the airline practice of giving local times without specifying the timezone. IMHO, any representation of time must always specify the time zone, preferably as an offset (e.g., -0700) or at least as a zone (e.g., PDT or MST). The only situation, again in my opinion, where it would be acceptable to omit the time zone or offset is when UTC is used. This would only be practical in situations where only UTC is ever used, again because of the common practice of giving local times without a timezone indicator.
Past the 12th day of the month it doesn't matter! But yeah, otherwise it is one date or the other. The Europeans seem to always use day, month, year but here in the states we don't. I wonder how that got started. D M Y over the top of the box for the date on a QSL card is a nice touch. I always feel like just pitching QSL cards that have local time on them but I don't. Computer logging programs often use the colon in the UTC time but I never would when writing it on a card. I make no references to offsets or local time on a card or in a log. I suspect there is a programming reason that computer logging of time has the colon.
When I was QSL manager for our club, I always insisted a DAY, 3 letter abbreviation of the month, and full year. THAT way, there was no confusion if 10/8/19 meant the 8th of October, or the 10th of August. 10 Aug 2019 leaves NO confusion, nor does 8 Oct 2019. (At least, it shouldn't.) Added: BTW, UTC is just THAT. No letter offsets, etc. UTC is UTC, no matter where you happen to be.
++++++ You confuse UTC and Zulu time. there are 24 Zulu zones, any other adjustments are LOCAL time. there are many UTC zones where they vary the local time by 1/2 hour, some even 15 minutes, but, they are in the same Zulu zone
