April Fools

Of course it is raining today.
The text of the card translates, to the best of my ability, as:
April 1st. Threshold of spring, April says to the fish: sow joy, and leave the harvest to others!
On the reverse of the card is written in French:
Little Rora,
Receive best wishes for April 1st from all your good friends from 83 rue Galilee as well as those of Maman Jars who says to you, until next week. Many kisses from all, Maman Jars and Louillaud. The card was sent to Bordeaux, France. There is no stamp or postmark. I may have the names wrong as I find the capital letters a little hard to read.
From a brief internet search, I find that April Fool's Day most likely originated in France. One tradition is to tape a picture of a fish to someone's back. Seems a fairly quaint and harmless prank, n'est-ce pas?