April Fool’s Day is tomorrow, April 1, and I already know which of my family and friends to be on the lookout for. For some, April Fool’s Day is a high holy day, and they come to it fully prepared.

In fact, April Fool’s Day has become a day that some marketers get to show their creativity and their cheekiness. For example, in 2009, the Swiss Tourism Board released a video explaining why the mountains in Switzerland were so clean. In case you’re interested, it is because of the hard work of the Association of Swiss Mountain Cleaners, who clean bird droppings and other unsightly blemishes from the pristine Alpine slopes. (To see this video, and for a list of 99 other great New Years’ Day Pranks, click here.)

The first reference to April Fool’s Day comes from Geoffrey Chaucer’s “Canterbury Tales.” The Nun’s Priest’s Tale is set on a date “syn March was gon.” In other words, “since March was gone,” or—most readers surmised—April 1. In this tale, the fox tricks the vain cock Chanticleer. It’s the first April Fool’s prank.

Other references to pranks and jokes found their way into medieval literature. But writer Peggy Fletcher Stack says we owe the modern and widespread acceptance of April Fool’s Day to a pope. She writes in the Huffington Post: “The day began, most believe, in 1582, when Pope Gregory XIII decreed the adoption of the ‘Gregorian calendar’—named after himself—which moved New Year’s Day from the end of March to Jan. 1. The change was published widely, explains Ginger Smoak, an expert in medieval history at the University of Utah, but those who didn’t get the message and continued to celebrate on April 1 ‘were ridiculed and, because they were seen as foolish, called April Fools.’”

In the 14^th and 15^th centuries, some in the Catholic Church celebrated the so-called “Feast of Fools.” The idea behind the feast was honorable and even biblical. 1 Corinthians 1:27 says that “God has chosen the foolishness of this world to confound the wise.” The “Feast of Fools” originally celebrated that reality, though over time the feast (which didn’t happen on April 1, but at the New Year) became a focus for anti-clerical sentiment, and the Roman Church banned the feast in the 15^th century.

Today, April Fool’s Day is observed in most of the countries of the world, though it is not a formal holiday in any country. It’s a day for jokes, pranks, and hoaxes. It is also a healthy reminder (if you ask me) that we are all fallible, and we shouldn’t take ourselves too seriously.

Image courtesy of Wikipedia.

Warren Cole Smith is an investigative journalist and author as well as the Colson Center vice president for mission advancement.