The meaning and origin of 4/20, the biggest cannabis holiday of the year (2024)

420 started a secret stoner code during an era of persecution. Today, it’s a global celebration. Follow the long strange trip of 420.

What is 420?

Every year on April 20 (4/20)—a.k.a. “Weed Day”—cannabis enthusiasts celebrate their favorite plant with festivals, protests, marches, and smoke-outs great and small. But what are the origins of this high holiday? How do you celebrate it? What does “it” mean? And where is it heading?

It started as secret slang shared only among a select group of like-minded friends. It became an international day of cannabis celebration. The origin story of 4/20, or just 420, is as delightfully and defiantly anti-establishment as you’d hope—with a big dab of weedy whimsy dropped in the mix.

For starters, 4/20 is not a “Hallmark holiday.”

Far from it, Dude.

4/20 is a true pothead holiday, with deep roots in underground grassroots cannabis culture.

Today, dispensaries tout 4/20 blowout sales, and corporate brands like Ben & Jerry’s, Burger King, Denny’s, and Chipotle latch on to the marketing potential of a day when more people get more high than any other (munchies!). However, the customs and rituals of 4/20 came from underground networks like the Grateful Dead parking lot scene, early online message boards, and peer-to-peer smoke seshes.

What is the origin of ‘420’ Day?

Let’s start by dispelling a few common myths.

420 is not:

• Police dispatch code for cannabis smoking in progress
• A penal code for cannabis possession
• The number of chemical compounds in cannabis
• Proper “tea time” (4:20pm) in the United Kingdom
• The birthday (April 20) of Bob Marley, Jerry Garcia, Billie Holiday or any other notable cannabis celebrity.

The true tale of 4/20 is far weirder and kinder than all of the above.

Our surprisingly well-documented story begins in the fall of 1971 in San Rafael, California, when a crew of wisecracking, weed-smoking students, known as the Waldos, got ahold of a treasure map.

Turns out one of the Waldos had a friend whose brother was in the Coast Guard at the time, stationed nearby at the Point Reyes Lighthouse. For years, this Coast Guard cadet had been planting a small patch of pot in a forgotten area of federal land near the remote outpost. As harvest approached this time around, he got paranoid. He feared his commanding officer would follow him into the wilderness and bust him.

So the scared cadet drew a rough map showing where to search for the pot patch. The cadet gave the Waldos permission to harvest the crop for themselves before the rains came and the buds rotted.

With this treasure map in hand, the Waldos met at 4:20 pm on a fateful autumn afternoon, under a statue of Louis Pasteur, to get high and gather their forces before setting out in search of the secret weed garden. Together, they spent the next few weeks questing after this Holy Grail, only to come up empty each time.

Still, the outings served their larger goal of having grand adventures they called Waldo Safaris. Passing each other on campus, they took to using the phrase “Louis 420” as a coded reminder of their meeting time and place whenever a new search party was organized.

Eventually they dropped the “Louis.” And they never found the weed plants. But 420 took on a life of its own.

Why do stoners celebrate on April 20th?

The transformation from a time of day to smoke weed to an entire day of cannabis revelry can be easily explained. April 20th is 4/20, as commonly abbreviated in the United States. But how, exactly, did a silly in-joke among a single stoner crew evolve into a truly global phenomenon?

The very same way high-quality cannabis seeds spread from Northern California to the rest of the country back in those heady days of the early 1970s—by hitching a ride on the Grateful Dead’s traveling psychedelic freak show.

As Waldo Dave (not his real name) explained to Huffington Post’s Ryan Grim:

“The Grateful Dead had this rehearsal hall on Front Street in San Rafael. So we used to go hang out and listen to them play music and get high while they practiced for gigs…. There was also a place called Winterland in San Francisco where we’d always be backstage running around or onstage and, of course, we’re using those phrases. When somebody passes a joint or something, ‘Hey, 420.’ So it started spreading through that community.”

With the Grateful Dead touring incessantly to large crowds over the next two decades, the seeds of 420 scattered far and wide, and then began to sprout, take root and spread. Not through the mainstream media (which didn’t know and wouldn’t care) or social media (which didn’t yet exist), but via a peer-to-peer network known as the smoke sesh.

Ceremonially getting high at 4:20 (AM or PM) became a true grassroots movement back when the phrase “grass roots” meant something. A meme before the internet. The ultimate “if you know you know” for those in the know about cannabis.

Back then, the phrase “420” also served as a clandestine way for fellow aficionados to self-identify in a time of heavy repression. You could slip a “420” into conversation in front of any authority figure and feel confident that only your fellow enthusiasts would pick up on the reference.

As cannabis culture came further and further out of the shadows, however, the coded nature of the communication fell by the wayside, and 420 morphed again, into a day of public celebration.

How is 4/20 celebrated with weed?

As long as you’ve got some weed to consume and some extra to share, there’s really no wrong way to commemorate 4/20. That said, there’s certainly some pot-holes you’ll want to steer clear of on the high holiday, particularly if you’re not used to being high AF out on Main.

First and foremost, smoke with your head—not over it. Go out and rep weed loud and proud, just make sure your cannabis intake stays well within your cannabis tolerance (especially when dealing with dabs and edibles). Also, keep yourself fed and hydrated, pace yourself to last till 4:20AM, and alway use the bud-dy system so you don’t end up “one toke over the line” all by your lonesome.

If you can’t find a 4/20 celebration near you, go ahead and start one, even if it’s just a few friends getting together to blaze out in the woods, or a parking lot behind a bowling alley. Remember—from the jump—420 has always been a grassroots DIY phenomenon.

If there’s one thing weed people know how to do, it’s make our own fun. In large part because we’ve been kept out of polite society for so long. So feel free to join an existing 4/20 celebration or start your own.

What does it mean for something to be 4/20-friendly?

The phrase 420-friendly dates back to a transitional moment in the 420 timeline, when the phenomenon remained underground, but just barely. In the late 1990s, cannabis itself was barely-legal in just a handful of states with medical cannabis laws, while at the same time the internet was emerging as a new way for people to connect.

From finding an apartment share on Craigslist to seeking a romantic partner on first-generation dating apps to posting a temp position on the earliest job boards, the phrase “420-friendly” let people bat-signal their acceptance of cannabis consumers without necessarily alerting those who might object.

For the first time, this put 420 in the public sphere, where the squares were bound to eventually crack the code. On the one hand, this ended the era of 420 as insider lingo—which was kind of a bummer, man—but on the other hand it gave cannabis culture a whole new form of visibility.

It’s easy to forget, at this increasingly 420-friendly moment in history, that at one time cannabis consumers faced not only prison, but stereotyping and stigma. At the heart of this denigration was the paradox that responsible, succesful stoners hid in the closet for rightful fear of arrest and other negative outcomes from admitting that they like to get lit.

Seeing “420-friendly” start to pop up on the internet forced a conversation about who really smokes weed. Turns out, like all stereotypes, the public shaming of cannabis smokers had been based on lies and distortions. Which explains how quickly public perception began to shift once everyone who didn’t smoke weed found out how many people do, including some of the smartest and most accomplished people on Earth.

And yes, also some of the friendliest. No studies exist to confirm that weed makes you more friendly, or that friendlier people smoke more weed, but there’s plenty of anecdotal evidence indicating that both are true.

But really, you don’t even have to smoke weed to be considered 420-friendly, it just indicates that you accept cannabis people as your equals and appreciate cannabis culture as a positive force in the world. All of which means, no, you don’t have to get high at all to properly celebrate 4/20—but it sure does help.

Learn more than you’ll remember about Leafly Nation’s Independence Day with our Ultimate 420 Guide.

This article first appeared in 2017 and we re-wrote it in 2023.