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. But on March 31 leap year (a year which has 366 days including February 29 of varying sophistication on friends, enemies and neighbors, or sending them on ). The day is marked by the commission of hoaxes and other practical jokes fools' errands, the aim of which is to embarrass the gullible.

César Estrada Chávez (March 31, 1927 – April 23, 1993) was a Mexican American farm worker, labor leader, and civil rights activist who with Dolores Huerta co-founded the National Farm Workers Association, which later became the United Farm Workers. Supporters say his work led to numerous improvements for union laborers. He is considered a hero for farm laborers, and opposed both legal and illegal immigration to help keep wages higher and improve work safety rules. He is hailed as one of the greatest American civil rights leaders. His birthday has become a holiday in four U.S. states. Many parks, cultural centers, libraries, schools, and streets have been named in his honor in cities across the United States. Click here for Cesar Chavez time line