Whataburger on the moon? San Antonio staples pranked followers on April Fools' Day FacebookTwitterEmail Several local businesses and organizations got into he April Fools spirit and took to social media Thursday to have some fun with their followers. The Bexar County Sheriff's Office told its followers it nabbed a unicorn during a drug bust, while Taco Cabana touted a "new" giant margarita. April Fools' Day has been around for centuries, though its exact origin is unknown, according to The History Channel. Some historians believe it dates as far back as 1582, when France switched from the Julian calendar to the Gregorian calendar. Those who didn't receive the news that the calendar year no longer start on the last week of March became the bud of some jokes.