The UK (and Europe) has been pretty lucky when it comes to the Marvel movies, because they always get released about a week before the US. With Infinity War things have changed, seeing as how Marvel Studios brought the US release up a week to 27th April. But it looks like we'll still be getting the film before the Americans, though the gap is only a single day.
This is all according to Yahoo UK, which is reporting Marvel and Disney have made the change. Though as it points out Marvel UK was still using the 27th April date as late as Wednesday.
#CaptainAmerica, #BlackWidow, #Bucky, #BlackPanther and #Okoye prepare for action in this exclusive image from @totalfilm! Who's excited for #InfinityWar? In UK cinemas April 27 pic.twitter.com/w0LNwNlnJw
— Marvel UK & Ireland (@MarvelUK) March 7, 2018
Though IMDB claims other countries like Australia, France, Belgium, Sweden, New Zealand, and others will get to enjoy the film on 25th April, so it's not like the first members of the film-going public to see the film will be us. Though I have noticed that 27th April is a Friday, and if you've ever paid attention to film release schedules Friday releases don't seem to happen that often. It's never been clear why, and while some big films do come out at the end of the week, like Star Wars: The Last Jedi, that's clearly because Friday is a big release date in the US and studios want parity for one reason or another.