Primary school, known as “elementary school” outside of Québec, is a great opportunity to learn about most holidays. As kids, we learned quite early that April 1st was “Poisson d’avril”, or “April’s Fish” for a direct translation. Mostly, Poisson d’avril is the same as April’s fool, but we draw fish on pieces of paper, and stick them on people's backs without them knowing.
Until recently, let’s say this morning to be really honest, I thought the fish thing was recognized widely in the Western countries. Turns out it isn’t. ”Eh ben”. Knowing that for most people, the relation between April 1st and fish will be hard to get, it was a great opportunity for me to research a little and write about it. Turned out there is nothing sure regarding what you are about to read, so please use this information wisely.
Apparently, there was a time in history when the new year was celebrated at the end of March, celebrations ending on April 1st, it was the Julian calendar (as in Julius Caesar). Around 1500, Pope Gregory XIII would introduce the Gregorian calendar with the king of the moment, I think it was Charles something, starting on January first. Without the Internet, this kind of change would be harder to implement, so many people would still celebrate on April 1st and be in the wrong. Those who knew about it would roll on the floor laughing and they would mock the fools as April Fools. Sounds like it stuck.
Regarding the fish implication, it’s not clear. It’s either that fish are abundant in April and easy to catch so anyone being fooled is called a fish, or either they haven’t reproduced yet and very rare, and anyone pretending to eat some is pranking you. It can also be that around Easter, people were forbidden to eat meat so they would eat fish instead and would be all over this slimy animal, even gifting fish to each other, until real fish turned into paper fish and ended up taped in people’s back. Weird. Pick your favourite. Whatever the origin story, it led to making pranks on people and to some fish pedals being discounted.