But it also tweaks a few other bits and pieces under the hood, which fans are only finding out about while playing.
Most notable, perhaps, is the game's warning you will now earn a lower rate of interest on savings in your ABD bank account. You'll get a letter in the post about this (which is scarily similar to the one my bank sent me this week telling me exactly the same thing).
This is likely to counteract players using sneaky time travel methods to notch up piles of money via decades of interest. Which, you know, is just cheating.
In recompense, you'll get a free Bell Bag Rug from the bank with the letter to decorate your home.
Other additions include a trio of familiar-looking aloha shirts as worn by Isabelle, Timmy and Tommy via Nook Mile rewards (600 Points each) and a new hedge fence for today's Nature Day event.
Finally, whether you get Redd in your town today or not, a trip to the museum will see Blathers inform you he's now accepting art donations, with a view to opening the gallery section. Just beware forgeries...