"It's hard to believe that four years have passed since Overwatch's monumental release, but another anniversary event is here to remind us with another all-encompassing annual celebration of Blizzard's beloved hero shooter. The 2020 anniversary event comes with some unique skins, including skins and other cosmetics you may have missed from previous events, along with PvE activities and much more."
"Overwatch's new anniversary event will kick off on Tuesday, May 19. The event will technically start a couple of days before the game's true anniversary, which is May 24, because Blizzard always updates the game on a Tuesday rather than a Sunday. A specific start time hasn't been officially confirmed, but most updates and events begin around 1 p.m. to 3 p.m. Eastern, so it's likely that this anniversary celebration will follow suit."