Why are we talking about April Fools?
You are probably wondering why in France we talk about « April fishes ». In reality we are not clear on where this expression comes from. There are several theories about this. But in my humble opinion, the reason is probably a mix of the following 3 theories:
The first would be that at one point the year began on April 1. In 1564, King Charles IX decided that the year would begin on January 1. But of course it took a while for everyone to accept this change. And in the meantime a lot of people continued to give each other small « hansel » for New Years (gifts we offer for the New Year) on April 1st. For those who were much more progressive and accepted change more easily, these people deserved a little joke, so they gave them fake gifts to make fun of them. But what does this have to do with fish? Well, April 1 usually comes around the end of Lent, when Christians aren't supposed to eat meat. Fish was therefore a very popular dish during this period. So the pranksters offered fake fish to those who continued to celebrate New Years Day on April 1.
The second hypothesis, much more concise this time, would be quite simply in honor of the last sign of the zodiac of winter and the first sign of spring : Fish. The first days of spring and their festivities would have brought jokes with them.
The last assumption is that in April it was forbidden to fish. So we offered fish and pretend that we had caught them to make a prank to the most naive.