The History of 420: Where Does the Most Famous Code in Cannabis Culture Come From?

Whether on a T-shirt, in a Tinder bio, on a cinema clock, or on social media, the number 420 (or 4/20) is recognized worldwide as the ultimate symbol for cannabis enthusiasts. Every year, on April 20 (written as 4/20 in the American format), gatherings take place across the globe to celebrate the plant precisely at 4:20 PM.

But where does this mythical number actually come from? Why 4:20 and not some other time? Between documented historical facts, urban rumors, and pop culture nods, here is the complete guide to everything about 420.

1. The True Story: The "Waldos" of San Rafael (1971)

For decades, dozens of theories circulated about the origin of the term. Yet, the real story is much simpler and more authentic. It dates back to the fall of 1971, at San Rafael High School in California.

A group of five teenagers—Steve Capper, Dave Reddix, Jeffrey Noel, Larry Schwartz, and Mark Gravitch—used to meet after school near a stone wall outside their school. Because of this meeting point, their classmates nicknamed them "The Waldos."

One autumn day, the group heard about an abandoned cannabis plantation near the Point Reyes lighthouse, planted by a Coast Guard member who could no longer tend to it. Armed with a handmade treasure map, the five friends decided to go looking for it.

Their meeting point? The statue of scientist Louis Pasteur in the high school courtyard. The meeting time? 4:20 PM, once classes and sports activities were over.

For weeks, the teenagers would pass each other in the hallways, whispering: "4:20 Louis" to remind each other of the rally. Over time, the word "Louis" disappeared, and the number "420" became their secret code for anything related to cannabis.

2. How did a high school fad become global?

A code used by Californian high school students could have disappeared with their graduation. Two major factors propelled 420 to international phenomenon status:

The Grateful Dead

The father of one of the Waldos managed the real estate of The Grateful Dead, the legendary psychedelic rock band. The brother of one of the band members was also friends with one of the Waldos. The teenagers thus began frequenting backstage at concerts and band rehearsals, spreading the word "420" among technicians and fans (the Deadheads).

High Times Magazine

In December 1990, during a Grateful Dead concert in Oakland, a team of fans distributed flyers inviting the crowd to "smoke 420 on April 20 at 4:20 PM." A copy of the flyer fell into the hands of Steven Hager, editor-in-chief of the famous New York magazine High Times.

In 1991, the magazine published the flyer and began systematically using the term in its articles. By formalizing the word, High Times transformed a local code into an indispensable international reference.

3. The Great Myths Around 420: True or False?

Around the phenomenon, many urban legends have emerged. Let's separate fact from fiction:

• "It's the California police radio code for cannabis": FALSE. Code 420 in California police refers to illegal occupation of public land or a disturbance on a public road. No direct relation.
• "It's the number of molecules in the plant": FALSE. Cannabis contains over 500 chemical compounds (including over a hundred cannabinoids). The number 420 does not correspond to any chemical data.
• "It's a nod to Bob Dylan": FALSE (but amusing). In his song Rainy Day Women #12 & 35, Bob Dylan sings "Everybody must get stoned." If you multiply 12 by 35, you get 420. While it's an amusing coincidence, it's not the origin of the code.
• "It's related to Bob Marley's death": FALSE. Bob Marley died on May 11, 1981, and was born on February 6, 1945.

4. 420 in Pop Culture and Unusual Anecdotes

Today, 420 has infiltrated popular culture everywhere, leading to some colorful anecdotes:

• The 419.99 sign in Colorado: On Interstate 70 in Colorado, the sign indicating Mile Marker 420 was so frequently stolen by collectors that the Department of Transportation replaced it with a sign reading "Mile 419.99."
• Hotel Room 420: Many hotels avoid numbering a room "420" or paint the number directly on the door to prevent the metal plaque from being stolen.
• Pulp Fiction: In Quentin Tarantino's cult film, most of the clocks visible on screen are stopped at 4:20.
• The Simpsons: In several episodes, the kitchen clock or Homer's alarm clock displays 4:20.
• Reddit and Snapchat: April 20 is considered the "holy day" of online memes, where communities worldwide share humorous content and messages.

5. What Does 420 Represent Today?

Beyond a simple festive connotation, April 20 (4/20) has become a global day of gathering, cultural expression, and advocacy for the legalization and decriminalization of cannabis worldwide.

Peaceful gatherings take place every year in major cities like London (Hyde Park), Vancouver, Denver, and Amsterdam, bringing together tens of thousands of enthusiasts who come to share a moment of conviviality.

Whether you're simply curious or a connoisseur of botany, 420 remains, above all, a symbol of camaraderie, relaxation, and respect for the plant.