The month of Venus begins with April Fool's Day (also known as All Fool's Day), an occasion for playing practical jokes on friends, family, and coworkers. This custom dates back to olden times, when inmates of insane asylums were allowed out in the streets for one day each year for the sadistic amusement of those who were (supposedly) normal.
April 1 is one of the few days of the year that has widespread secular observance (the others being Halloween, Christmas, and New Year's). In every society there are periods of time when misrule or disorder is permitted, even encouraged, for a short well-defined term to prevent things from becoming too rigid. In the Northern tradition, the trickster god is Loki; the trickster is the model for playing tricks and practical jokes on people and making them into April fools.
Although Loki could often prove to be more than troublesome he could also do things that no one else could do. In the royal courts, it was often the court jester that was the only one that could speak the truth~through the guise of jest~he was often closest to the king and could make his observances without fear of reprisal.