When it comes to anime, new shows are released four times a year, with the Winter season starting in January, the Spring season starting in April, Summer starting in July, and then Fall season in October.
We currently don't have a specific release date for Season 4 Part 2 of Attack on Titan, but an announcement at the end of Season 4 Part 1 announced that the next episode was going to air in the “Winter 2022” anime season.
