The History of April Fools Day: Here are what folks say about the Origins of April Fools Day:

From Michael A. Nagurney It seems that it had no definite starting point, like Christmas or 4th of July. Rather, April Fools Day appears to have had a slow evolution toward modern day. It seems to be the result of the convergence of various cultural beliefs and practices which held a common theme, the emergence from the doldrums of winter. The first of April is recognized as a day of pranks not only in the United States, but also in France, Germany, and Great Britain. In India, the feast of Huli occurs in March. The final day of Huli is March 31, and is traditionally celebrated by acts of mischief. In France, a fool is sometimes called a "poisson d'Avril" (April fish). In Scotland, a fool is called an "April gowk" or "April cuckoo".

From Craig Minton On the way in to work this morning, they said on the radio that April Fools started back when they changed the calendar. They said at one point people used to celebrate the new year in April. When the new year was changed to January, they called the people who continued to celebrate the new year in April, April Fools. Don't know if it's true...just what I heard.

From Nilda R. Cano April Fools is also celebrated in some Latin American countries, such as Peru and Colombia. It is celebrated on December 28, hence its name is not "April Fools" . It is called "Dia de los Inocentes" which in English it would be "The Candids' Day". The pranks are the same. Have a happy one.