April 1st is known the world over as April Fool's Day; that day when tricksters and prank pullers have licence to exact acts of mirth and merriment upon the world. My first and only thought is to put a bucket of water on top of a door so that someone gets wet when they walk in but sanity and the fear of retribution means that I will never actually do it.
The thing that perpetually eludes me is why this day exists. All reasons given seem to explode upon contact with any remotely tenuous fact; which makes an explanation even harder to pin down.
The Roman Empire under Julius Caesar changed the names of several months and reset the beginning of the year to January 1st. The Romans had all sorts of calendaric jiggery pokery which included mucking around with the idea and kalends and adding days upon what was mostly the whim of the emperor. The system was generally pretty rubbish and at some point, depending on where you were in the empire or post empire, the year either began on December 25 which was considered to be the Winter Solstice and as good enough as any to declare Christmas, or March 25 which was considered to be the Spring Equinox.
A pope called Gregory XIII (who was originally named Ugo Boncompagni and who had an illegitimate son after an affair with a lady called Maddalena Fulchin; which is a very popey thing to do) thought that the whole calendar was quite a bit naff because the seasons kept on going in and out of phase with the months and being pope, he had enough of a political sway across Europe to impose the current calendar which again set January 1st as New Year's Day and gave us the current system for adding in leap days once every four years.
The story which is usually told us that people who still thought that New Year's Day was April 1st were made fun of and hence the reason why we have April Fool's Day... except that this is nonsense. Nobody ever used April 1st as New Year's Day; because as I've just stated, the New Year's Day which was used in some places was March 25. There is still an appendix of evidence for this in the UK tax year which begins on April 6th but prior to 1752 when England joined the rest of Europe on the new calendar, the tax year was the same as the calendar year which began on March 25. In 1752, England had a leap of eleven days and Sep 2 was followed by Sep 14.
I've read things about Huntinggowk Day in Scotland which is literally "Hunting Gowk (Idiot) Day" but that seems to have sprung up after the event. There is also a theory that it might be French in origin but I don't see how this makes any sense either. This theory rests on the idea that there was a week long festival for the new year in France and that April 1st came at the end of it. While that bit is true, when France adopted the Gregorian calendar, then people still celebrating the new year on the old date, would have done so on March 25.
So in reading stories that don't make sense, theories which don't square with evidence and logic; the only conclusion that I can draw is that the biggest prank being pulled on April Fool's Day is the existence of April Fool's Day itself. Go figure.