I know the UK is 11 hours behind New Zealand time. I googled it on my phone. I have a few girls on my Xbox 360 friends list who live in the UK. It's currently Monday 23 May 6:54 pm here. Tomorrow is Tuesday. I might stay up till 11:30pm tomorrow. By then, it will be Tuesday 24 May 12:30 pm in the UK. If they release it before 12:30 pm UK time, I'll be able to play it tomorrow. Sydney Australia is 2 hours behind New Zealand time. If not, I guess that's kind of false advertising saying something is out a particular day when it won't be. I know some companies/game developers, etc, try to take into consideration how forward time is in Australia and New Zealand, is with the rest of the world. I contacted Xbox Support as they said a particular Xbox 360 game would be out on a certain date. And they managed to get it out on the same day. But then again, Frontier could release it at 5 pm UK time, 3 pm, or 9 am. On Xbox One, new releases generally release or become playable, when it hits 12:01 am on the morning of a game's release date. But some games are soooo American or something that it won't be out until it's the release day in that country.
I'm not going to throw a huge fit if it doesn't come out before I need to go to sleep tomorrow night. The game could come out in the UK when NZ/Australia are in bed or the following day in school or work. Or it could come out when NZ/Australian peps like me are having dinner. Imagine if Frontier was in Australia or NZ. Then we'd definitely be the ones to get it first.