April 20 (4/20 or 420) is “National Pot Smoking Day.”

National Pot Smoking Day is a day where people all over the world celebrate by smoking marijuana. It’s an unofficial holiday that is based on the simple concept of smoking cannabis and being happy.

There are several different versions of the story about how National Pot Smoking Day got started, but I’m inclined to go along with the editor of High Times, Steven Hager.

His story is that the term “420″ got started at San Rafael High School in 1971 when a group of about a dozen pot-smoking students calling themselves the Waldos would meet after class at about 4:20 in the afternoon to smoke pot near the campus statue of Louis Pasteur. They made 420 a code for the time to get high, and the 420 code’s use spread throughout an entire generation, even going so far as to be mentioned in the music of Jerry Garcia and the Grateful Dead.

Other versions say 420 originated from the police dispatch code that identified pot smoking or that 420 was the number of chemical compounds found in pot.

Whatever the case may be, if you’re a connoisseur, dust off the Bob Marley vinyl, twist one up and be happy. 420.