April Fool/April Fools’ Day
Traditionally the first day in April is known as April Fools’ Day. References and citations for the first of April as April Fools’ Day go back as far as the 1500s but they are infrequent and in etymological terms such references are known as outliers because of their sporadic rather than general usage. There is no reference to it in any of Shakespeare’s works. First citations for April Fools’ Day only appeared on a regular basis from the late 1600s onwards although the practice of playing jokes and pranks on people was well established long before this and stretches back to ancient times. Setting aside a day on which to play pranks and jokes on people are common to many cultures across the world but the first of April appears to be mainly a European and English-speaking world phenomenon. For those interested in reading all the theories about the origin, none of which are proven beyond doubt, the Museum of Hoaxes website has put together an excellent compilation at http://hoaxes.org/af_database/permalink/origin_of_april_fools_day.