Almost everyone has heard of 420, but how many actually know the origin of how this iconic date came to be?

This popular marijuana celebrating holiday was created in 1971 by five high school students in San Rafael, California. The five friends used the term 4:20 as code to go searching for an abandoned cannabis crop, from a treasure map that was created by a grower. The group of students called themselves the Waldos, after their local hang out spot — by the wall of their school. They would meet at 4:20pm at least once a week by the Louis Pasteur statue outside school to begin their hunt. The secret term ‘420 Louis’ was used as the group would gather in a car, smoke weed and search for the infamous plant. After awhile the students decided to drop the ‘Louis’ and just use ‘420’ as the code word so their parents and teachers would not become aware of them smoking cannabis. After many failed attempts of finding the cannabis plant they ultimately evolved the code to refer to consuming cannabis.

But how did this term become the global phenomenon it is today? In 1990, at a Grateful Dead concert, a reporter from ‘High Times’ by the name of Steven Bloom received a flyer. The flyer stated, “We will meet at 4:20pm on 4/20 for 420ing”, and explained the history of the Waldos. High Times grabbed the story and launched this unofficial holiday worldwide.

Fast forward 50 years, and here we are celebrating the 50th anniversary of 420.