The exact origins of April Fools’ Day are uncertain, and there are several theories about how the tradition began. One popular belief is that it dates back to 16th-century France when the country switched from the Julian calendar to the Gregorian calendar, as called for by the Council of Trent in 1563. In the Julian calendar, New Year’s Day fell around the end of March or early April. However, with the adoption of the Gregorian calendar, New Year’s Day was moved to January 1st.

According to the legend, some people either refused to accept the new date for New Year’s Day or remained unaware of the change. Others would mockingly exchange gifts and play pranks on those who celebrated the New Year in the spring. Over time, this evolved into a tradition of playing practical jokes on friends and family.

Another theory suggests that April Fools’ Day has roots in ancient celebrations of spring, where people engaged in playful and mischievous behaviour as a way to welcome the arrival of the new season.

Regardless of its precise origin, April Fools’ Day has become a widely recognized and celebrated day for pranks and jokes in many countries around the world. People play practical jokes on each other, media outlets publish fake news stories, and businesses sometimes participate in the fun by promoting humorous products or services. It’s a day that encourages lightheartedness and laughter, with participants often saying “April Fools!” after revealing their pranks.

One of the most famous April Fools’ prank involved San Serriffe – a fictional island nation invented for April Fools’ Day 1977, by The Guardian newspaper. It was featured in a seven-page hoax supplement, published in the style of contemporary reviews of foreign countries, commemorating the tenth anniversary of the island’s independence, complete with themed advertisements from major companies. The supplement provided an elaborate description of the nation as a tourist destination and developing economy, but most of its place names and characters were puns and plays on words relating to printing (such as “sans-serif” and the names of common fonts – the capital city was Bodoni). The original idea was to place the island in the Atlantic Ocean near Tenerife, but because of the ground collision of two planes there a few days before publication it was moved to the Indian Ocean, near the Seychelles islands. The authors made San Serriffe semi-colon shaped and a moving island – a combination of coastal erosion on its west side and deposition on the east causing it to move towards Sri Lanka, with which it would eventually collide, at about 1.4 kilometres per year.

San Serriffe was one of the most famous and successful hoaxes of recent decades; it has become part of the common cultural heritage of literary humour, and a secondary body of literature has been derived from it.