Every year, cannabis aficionados gather to celebrate the weed holiday that falls on April 20th. There is a lot of mystery behind the history of the holiday, its exact origins, and why the date became so culturally connected to cannabis. While the facts are a little murky, here’s everything we know about the holiday, which officially takes place next Monday (if you haven’t already been celebrating all month, of course).

Origins of 420

There is a lot of speculation surrounding the origin of 420 as a weed holiday. Most people don’t really know where it comes from or why we celebrate it, but odds are they’ve heard a few vague stories about how everything got moving. If you ask around, you’ll get a variety of answers. Some claim it has to do with Hitler’s birthday since it shares the same date (but nobody knows why), while others claim it has to do with the specific time people drink tea in Holland (specifically, Amsterdam). Some believe it’s the number of active chemicals found in cannabis (though science has found a lot more than that).

However, most people believe it has to do with Bob Dylan’s “everybody must get stoned” refrain from the song “Rainy Day Woman No.12 & 35” which equals 420 when multiplied. In reality, music has a fair bit to do with the spread of the holiday, though it wasn’t Bob Dylan’s -- it was the Grateful Dead. We’ll touch more on that later.

The true origin of 420 is traced back to a couple of California teenagers who used to meet each other at 4:20 PM outside their San Rafael school. The teens, nicknamed “the Waldos”, coined the term in 1971 to discuss cannabis use discreetly around teachers and parents.

It all started when a Coast Guard member abandoned a cannabis crop they could no longer care for. The Waldos received a treasure map that would supposedly lead to the crop and would meet each other at the Louis Pasteur statue outside of their high school after football practice around 4:20 PM to search for it.

While they ultimately never found it, The Waldos would get together, smoke weed, and search the forest for the free crop. One of the original members of the Waldos, Steve Capper, told the Huffington Post, “We would remind each other in the hallways we were supposed to meet up at 4:20. It originally started out 4:20-Louis, and we eventually dropped the Louis.”

Why 420? For one thing, it was a police code for marijuana use in progress at that time. It was also the time the Waldos used to get together and smoke.

Why it is Celebrated as a Holiday

Music helped spread the slang term the Waldos coined. As we mentioned earlier, a lot of it actually had to do with The Grateful Dead. The Waldos were connected to many of the band members and spent a lot of time around them.

Capper told the Huffington Post, “There was a place called Winterland, and we’d always be backstage running around or on stage and, of course, we’re using those phrases. When somebody passes a joint or something, ‘Hey, 420.’ So it started spreading through that community.”

During a Grateful Dead show, a deadhead handed a flyer to a reporter at High Times magazine that explained the story of the Waldos and the history of the term. It said “We are going to meet at 4:20 on 4/20 for 420-ing in Marin County at the Bolinas Ridge sunset spot on Mt. Tamalpais.” and went on to discuss that 420 is a cannabis holiday to be celebrated.

Once High Times published the story, 420 became an unofficial holiday in the cannabis community. Today, the unofficial holiday is celebrated worldwide.