Probably more widely-known here as part of this achievement than the actual day itself, it's St. Roch's day tomorrow. This means it's nearly time to pay a visit to the Calendar Man in Batman: Arkham City
for those looking to earn the game's Storyteller achievement.
Visiting him will mark off one of the twelve dates needed to unlock the achievement on Xbox 360, Xbox One and PC.
Go give Calendar Man a quick visit in the courthouse cells tomorrow.