IPK. Yahoo Groups. Holidays. McGraw-Hill Professional - About the Holidays: Histories of Sele. April Fools' Day (April 1) (Also called All Fools' Day.)
April Fools' Day seems to have begun in France in 1564. Apr 1 used to be New Year's Day but the New Year was changed to Jan 1 that year. People who insisted on celebrating the "old" New Year became known as April fools and it became common to play jokes and tricks on them.