Fronleichnam
I could Google it and find out what in the world that is. But I’m actually enjoying the mystery a little. I can tell you it’s the reason I get work off on Thursday, when seemingly everyone else still has to work.
For those of you who don’t know, Germany has a very fair way to decide what days are holidays. The majority of each province effectively “wins”, and whatever holidays are associated with their religious beliefs are the official ones. So here in the southern-most province of Germany, Bayern, the majority is Catholic. That means that people working in Bayern get holidays that aren’t celebrated in the neighboring province, Hessen (think Frankfurt) - since Hessen is majority Protestant. This is a useful way to maintain separation of church and state; by treating religion as part of culture, the big religious holidays can be days off work without making the things they stand for part of what the government stands for.
Of course, if you work in Bayern and your partner works in Hessen, there will be a few days in the year your holidays don’t match. But who cares? Just means you’ll get the house, the TV, and the sun or snow to yourself for those extra hours :)