What is April Fools Day and how did it begin? Well, that is a very good question. The origin
of this holiday is rather uncertain. However, the common belief holds that during the reformation of the calendar the date for the New Year was moved from April 1st to January 1st.
During that time in history there was no television or radio so word spread slowly. There were also
those who chose to simply ignore the change and those who merely forgot. These people were considered
"fools" and invitations to non-existent parties and other practical jokes were played on them. "All Fools' Day" is practiced in many parts of the world with practical jokes and sending people on a fool's errand.
Others believe that the origin began with celebrations at the Spring Equinox.
In Scotland, April Fools Day lasts 48 hours, day two is know as Taily Day and pranks involving the posterior are played. The victim of the practical joke is referred to as "hunting the gowk"; the gowk is the extinct cuckoo bird. In France, he is the "poisson d'Avril" or "fish of April." The fish in April are newly hatched and easy to catch.
D�a de los Santos Inocentes is held in Spain on December 28th. This is The Feast of the Holy Innocents. It's celebrated similarly to April Fools'Day with practical jokes.
The first of April, some do say, Is set apart for All Fools' Day. But why the people call it so, Nor I, nor they themselves do know. But on this day are people sent On purpose for pure merriment. -- Poor Robin's Almanac (1790)