It's April Fools' Day! But when did it get started?

FOX News Radio's Tonya J. Powers has details:

Some historians say the day goes back to 1582. That's when France switched from the Julian calendar to the Gregorian calendar. Folks who were slow to get the update, or didn't realize the start of the new year had moved to January 1st and continued to celebrate during the last week of March through April 1st became the butt of jokes and hoaxes.

Others say it may be tied to the Vernal Equinox, or first day of Spring in the Northern Hemisphere, when Mother Nature fooled people with unpredictable weather.

Modern April Fools' pranks have included Taco Bell's 1996 announcement it had bought the Liberty Bell and changed the name to the Taco Liberty Bell... And Burger King's fake "Left Handed Whopper" in 1998.

Tonya J. Powers, FOX News Radio.