april fools...

@ 10:45AM April 1, USA time, Dom says: April Fools' Day or All Fools' Day, though not a holiday in its own right, is a notable day celebrated in many countries on April 1. The day is marked by the commission of hoaxes and other practical jokes of varying sophistication on friends, enemies and neighbors, or sending them on fools' errands, the aim of which is to embarrass the gullible.

The origins of this custom are complex and a matter of much debate. It is likely a relic of the once common festivities held on the vernal equinox, which began on the 25th of March, old New Year's Day, and ended on the 2nd of April.