A month of tree blossoms and light cardigans, birds twittering and taxes being filed. And, of course, peak harvest season for Switzerland's world-famous spaghetti crop, which, thanks to an exceptionally mild winter, was experiencing a bumper year in 1957.
If you're thinking, "Huh?" well, then, good on you for being better informed than the average BBC viewer at the time. When the British news network aired a 3-minute segment about Swiss spaghetti farmers plucking long strands of pasta straight from tree branches, hundreds of credulous viewers wrote in asking how they could cultivate their own spaghetti tree.
The BBC replied, with quintessentially British aplomb: "Place a sprig of spaghetti in a tin of tomato sauce and hope for the best."
"The Swiss Spaghetti Harvest" - which aired, unsurprisingly, on April 1 - has been declared one of the greatest April Fools' pranks all of all time. It was the first time any major news organization had used television to so thoroughly bamboozle its audience.
But it was not the first ever April Fools' joke, not by a long shot. Who exactly should receive that dubious honor remains in dispute.
Some historians believe that April Fools' Day has its origins in ancient Rome, with a festival known as "Hilaria." Usually celebrated on March 25, according to William Smith's "Dictionary of Greek and Roman Antiquities," Hilaria was a day for games, masquerades, and generally whiling away the day with relentless mocking - not even local magistrates were immune.
The two-day Hindu celebration Holi, the Persian festival Sizdah Bedar and the Jewish holiday Purim also fall in early spring. While not explicitly about tricking people, both holidays involve various forms of merriment and frivolity - throwing colored powder, picnicking outside, dressing in costume, etc. The Museum of Hoaxes (that exists) notes that there's no direct evidence that April Fools Day came from any of these celebrations: "Instead, it's more likely that April Fools' Day resembles these other celebrations because they're all manifestations of a deeper pattern of folk behavior - an instinct to respond to the arrival of spring with festive mischief and symbolic misrule."
Blame - or credit, depending on your perspective - may also lie with the Catholic Church and its "Feast of Fools," which was celebrated around Jan. 1 in medieval France and England. According to folklorist Jack Santino, who wrote a history of American holidays, church officials originally encouraged the carnival-like celebration, which involved reversing social roles, dressing in costume and bringing donkeys into church. They believed it helped "release pent-up anti-clerical sentiment among the people," Santino writes. But by the 15th century they decided the feast had become too raucous and banned it. Like any practice involving flouting authority and generally having a good time, the "Feast of Fools" did not die easily - it would be several hundred years before people stopped celebrating.
The church is also implicated in the most popular theory about the evolution of April Fools Day. It was Pope Gregory XIII, after all, who issued a decree in 1563 ordering that Christian countries adopt a standardized calendar. The Gregorian calendar moved the new year from the end of March to the first of January; people who continued to celebrate on the old day, either because it was the 16th century and word traveled slowly or because they simply wanted to be a rebel, were mocked as "April fools."
This meant different things depending on where you lived. In France, targets would be chased by children, who pinned paper fish on their backs and yelled "poisson d'Avril!" If you were in Scotland, you were likely to wind up with a "kick me" sign on your butt instead. (The Scots are credited with inventing the "kick me" sign, to the chagrin of unpopular substitute teachers everywhere.)
There are some flaws with this theory, namely that, according to the Museum of Hoaxes, the first unambiguous reference to April Fools' Day came in a Flemish poem published three years before the calendar switch was made. Titled "Refrain on fool's errand-day/which is the first of April," the poem told the story of an unscrupulous nobleman who sent his servant back and forth on several absurd errands on April 1.
Either way, by the end of the next century April Fools Day was so ingrained that people had to entirely stop attempting to achieve serious things on April 1. It's said that the Treaty of Warsaw, which established an anti-Ottoman alliance between Poland and the Holy Roman Empire, was backdated from April 1 to March 31, 1683, just to prevent any possible confusion.
Even Google - a geopolitical force that is surely on par with the Holy Roman Empire - is not immune. When it rolled out its email service on April 1, 2004 (notably, on the same day it sent out a job posting for positions on the moon), people assumed that the offer had to be a hoax. A whole gigabyte of storage for free? Not possible.
"Journalists would call us and say 'We need to know if you're just kidding, or if this is real,'" Georges Harik, who oversaw the development of new products at Google, told Time in 2010. "That was fun."