April Fools' Day is celebrated on April 1st by playing practical jokes. The history and origins of the holiday are unclear but it may have evolved from celebrations of springtime. In the 16th century, some people in France continued celebrating the new year on April 1st even after the calendar changed, and others played tricks on them for being foolish. Today, April Fools' Day jokes are meant to be fun and lighthearted pranks like putting toothpaste in Oreo cookies or changing the time on clocks.