Information from britannica.com

April Fool’s Day, in most countries the first day of April. It received its name from the custom of playing practical jokes on this day—for example, telling friends that their shoelaces are untied or sending them on so-called fools’ errands. Although the day has been observed for centuries, its true origins are unknown and effectively unknowable. It resembles festivals such as the Hilaria of ancient Rome, held on March 25, and the Holi celebration in India, which ends on March 31.

Notable April Fools’ Day pranks

In what may be the first televised April Fool’s Day hoax, the BBC aired a segment in 1957 that featured spaghetti-growing trees in Switzerland. The broadcast claimed that the dreaded spaghetti weevil had been eradicated, leading to a bumper crop of spaghetti. The BBC even aired clips of people “harvesting” the spaghetti. CNN later called it “undoubtedly the biggest hoax that any reputable news establishment ever pulled.”

The BBC was back at it in 1965 when it interviewed a professor who had invented “Smellovision,” a new technology that allowed for the transmission of aromas through a television screen. Following a demonstration, numerous viewers called the BBC to confirm that they had detected the scents.

In 1996 Taco Bell announced that it had purchased the Liberty Bell and renamed it the Taco Liberty Bell. The restaurant chain claimed that the acquisition was to help with the U.S. debt. (The Liberty Bell is actually owned by the city of Philadelphia, though the National Park Service [NPS] maintains it.) The news upset many Americans, and the NPS was forced to hold a press conference that refuted Taco Bell’s claim.

In 1977 The Guardian newspaper printed a travel supplement on San Serriffe, an island republic in the tropics. The text was filled with printing and typesetting terms—from the name of the island (inspired by sans serif typeface) to the shape of the island (a semicolon) to the island’s dictator, General M.J. Pica (the last name was a reference to a unit of typographic measurement).

In 1992 NPR declared that Richard Nixon, who resigned as president in 1974 amid the Watergate scandal, was entering that year’s presidential race. The radio network said his slogan was “I never did anything wrong, and I won’t do it again.”