420 is the code cannabis culture uses for weed and for the moment to smoke it: 4:20 in the afternoon. And because dates in the United States are written month first (4/20), 20 April has become World Cannabis Day. That much almost everyone knows; what almost nobody knows is where the number comes from, and the answer has nothing to do with the police or with the plant's compounds, but with five high-school friends from San Rafael, California, in 1971.
What does 420 mean? The number, the time and the date
- As a code: saying “420” means talking about cannabis, or about smoking, without naming it. It was born so that smokers could understand each other without parents, teachers or police catching on.
- As a time: 4:20 in the afternoon is the symbolic moment to light up. Everything else grows out of that.
- As a date: 20 April (4/20 in the US format) is the day the cannabis community gathers, campaigns and celebrates.
That is why a single number can be used to make plans with someone (“420?”), to mark a time of day and to flag a date on the calendar. And that is why, every 20 April, 420 spikes across the internet.
To those outside the cannabis world, “420” goes by as just another number, one that perhaps means nothing in itself. It could stand for anything: a weight, a price, a street address, a ticket number in the queue at the bank. In fact, there is no number without a meaning: by definition, it is a sign that always stands for something.
But here, in this cannabis fraternity, we all know what 420 stands for. Smoke, a sweet smell, a five- or seven-pointed leaf, a sticky flower, a joint being passed round a circle of friends.
420 is a wink, a not-so-secret code, a way of collective identification for all of us who orbit the world of cannabis. A shorthand for a conversation: what we talk about when we talk about spliffs. That is why, for a while now – we can't say exactly how long – every 20 April, in more and more places around the world, we celebrate something like Cannabis Day.
So, at 4:20 in the afternoon on the 20th day of the 4th month, users of this age-old plant all over the planet get together to honour the moment, or post some tribute to cannabis flower on social media. Instagram fills up with virtual smoke and animated GIFs, some radio stations play reggae, grow shops run discounts, rappers – from Snoop Dogg to Wiz Khalifa, and from L-Gante to Duki – fly the flag for the plant, and the whole blue planet called Earth turns a little greener.
Origin of 420
What is less well known, by the way, is where this number comes from, how it came about, why, and how the three digits that make up 420 – the message – became tied to the cannabis cause.
There is a lot of mythology around the 420 code. On the one hand, some say it was the code California police officers used to alert each other that they had a cannabis offence on their hands (“Marijuana smoking in progress”). For others, 4:20 is teatime in Holland; and some say 420 is the number of chemical compounds in the Cannabis sativa plant. But these are all failed theories. The truth about the origin of 420 lies in the spirit of five teenagers in the 1970s.
What is the true meaning of 420?
The true origin of 420 goes back to the 1970s in California, in the United States, where a group of young students at San Rafael High School used to meet at 4:20 pm to smoke cannabis.
Steve Capper, Dave Reddix, Jeffrey Noel, Larry Schwartz and Mark Gravich, a quintet who in their early youth called themselves the Waldos, are the only ones who can show physical proof that they had anything to do with the birth and heyday of 420.
The Waldos and the birth of 420
According to the story they have told over the last two decades, it all began one autumn day in 1971, at harvest time, when the Waldos heard that a member of the Coast Guard on the Point Reyes peninsula could no longer look after his (illegal) patch of cannabis plants.
As if it were a treasure hunt, word had it that the Coast Guard officer himself had drawn a map so that anyone who wanted to could find it. Somehow, it reached the Waldos, who decided to go after the green loot.
So the Waldos arranged to meet at 4:20 in the afternoon by the school's Louis Pasteur statue, since by then they could all make it in time after their various after-school activities.
Their first trips to find the plants were a failure, but the group didn't give up on getting that free cannabis. “We'd meet at 4:20, get into my old ’66 Chevy Impala and, of course, smoke all the way to Point Reyes. In fact, we smoked the whole time we were out there. We did it week after week,” Steve told the Huffington Post some time ago.
The story of 420, cannabis's secret code
The code they used among themselves for these outings started out as “4:20 Louis”, until only the number 420 survived. They never found the treasure, but the habit stuck, and the boys started meeting up to smoke by a wall outside the school (hence the name “Waldos”).
For them, “420” was a way of talking about cannabis without being understood by their teachers, their mothers or other classmates who didn't share the habit of using the sweet plant, at a time when society was far less tolerant than it is now.
The code could have been born and died with these five friends, but the universe has twists that defy logical explanation. San Rafael, the Waldos' Californian town, is 50 kilometres from the big city of San Francisco.
How did 420 become a way of talking about cannabis?
The Grateful Dead, one of the emblematic bands of California's hippie scene and late-sixties psychedelia, left the big city for a while and moved to Marin County, an area just a few streets from the Waldos' school. A twist of chance, or of fate.
The father of Mark Gravich, one of the Waldos, took over managing the Dead's property. Dave Reddix's older brother, Patrick, managed a side band that some of the musicians had put together with David Crosby, because he was close friends with the Grateful Dead's bassist, Phil Lesh.
That is how the Waldos started hanging around the legendary band's rehearsals and smoking cannabis with them. “So we used to hang out and listen to them play music and smoke while they rehearsed for concerts. I think it's possible that my brother Patrick spread 420 through Phil. And me too, because I was going out with him and his band as a roadie when they were doing a summer tour that my brother was managing,” Reddix said.
The Grateful Dead's role in spreading the term
The Waldos also got into the band's parties, so 420 was literally passed on by word of mouth. “We'd go with Mark's dad, who was a hip sixties dad,” Steve told the Huffington Post. “There was a place called Winterland and we were always running around backstage, or on the stage itself, and of course we used those phrases. When someone passed round a joint or something, it was ‘Hey, 420’.” That is how the term started to spread through that community, he said.
On 28 December 1990, a group of Deadheads (as Grateful Dead fans called themselves) in Oakland handed out flyers inviting people to smoke 420 on 20 April at 4:20 in the afternoon. One of those flyers ended up in the hands of Steve Bloom, a former reporter for High Times magazine, the world's first publication about cannabis culture. That was the start of the code's true global spread, almost 20 years after the original Big Bang.
How 420 went global: the first time 420 appeared in a cannabis magazine
The famous cannabis magazine High Times printed the 420 flyer in a 1991 piece and began referring to the term 420. The Waldos' code crossed borders and cultures and came back to where it started. The eternal return: in 1998, one of the Waldos came forward to say who they were, and a High Times journalist revealed, for the first time, the story of where 420 came from.
Finding the illegal treasure
The story could have ended there. But in 2016, after two years of digging, the Waldos finally met the owner of those illegal cannabis plants from their early days. He was Gary Newman, by then 68 years old. The old coastguard told them that, while he was stationed at Point Reyes, he looked after the local lighthouse and planted the famous patch on federal land very close to where he worked.
He grew for several years, but sure enough, in the autumn of 1971, the officer got scared of being caught by the police, and that was when he drew the treasure map and gave it to his brothers-in-law, Bill and Pat McNulty. It was Bill who passed the map on to Steve Capper. Ironically, Newman spent 45 years without knowing that his lost little plant was the inspiration and origin of a code that today is even more famous than the Grateful Dead.
The myths about the origin of 420 (and why they're false)
Before the Waldos' story became known, dozens of explanations did the rounds. None of them holds up:
- “It's the California police code for cannabis use.” False. No such code exists; 420 doesn't even appear in the penal codes it's attributed to.
- “It's the number of chemical compounds in cannabis.” Incorrect: the plant contains several hundred compounds, not 420.
- “It's teatime in Holland.” A legend repeated over and over with no real basis.
- “It's the ideal date to plant cannabis.” That depends on the climate and the type of growing; there is nothing universal about 20 April.
- “It comes from Hitler's birthday or Bob Marley's death.” Coincidences with no connection whatsoever to the origin of the term.
The only version backed by physical evidence — photos, a flag and references in the school yearbooks — is the Waldos'. In fact, the Oxford English Dictionary credits the origin of the term to “some students in San Rafael”.
How 420 is celebrated around the world (and in Spain)
What began as a private joke is today a global event. Each place lives it in its own way:
- United States: huge gatherings in the states where cannabis is legal, with heavy media coverage and political campaigning.
- Amsterdam: the European epicentre, with events in coffeeshops and meet-ups in parks such as Vondelpark.
- Spain: the approach is more about advocacy and information. In Barcelona and Madrid — where our physical stores are — cannabis associations organise gatherings, and many online shops launch promotions.
If you want to join in without stepping outside the law, 420 is a good time to discover CBD flower and CBD hash: the same ritual, within the legal framework of hemp.
From 420 to 710: cannabis's other number
If 420 belongs to flower, 710 belongs to concentrates. The trick is to read the number backwards or upside down: 710 spells out the word OIL, a nod to extracts and resins. Its day is 10 July and, although it is nowhere near as famous as 420, it is gaining ground among those who prefer concentrates.
Frequently asked questions about 420
What does “420 friendly” mean?
On dating apps, rental listings or social profiles, “420 friendly” means the person or place is tolerant of cannabis use. It doesn't imply any sale or anything illegal: it simply signals an open attitude towards 420.
Does 4:20 mean anything outside cannabis?
Many people see 4:20 on the clock and link it to signs or “love” messages. Beyond popular numerology, its only documented cultural meaning is the cannabis one: the time the Waldos chose to meet.
Is 420 the same as 710?
No. 420 is associated with cannabis flower and with 4:20; 710 with concentrates and oils, and it is celebrated on 10 July. They are two different codes from the same culture.
Is 20 April an official holiday?
It isn't officially recognised in any country, but it works as a symbolic worldwide cannabis day, with events and campaigns every year.
Today, 420 is far more than a time or a date: it's a symbol of unity, culture and resistance. At Cannactiva we celebrate it with our CBD flower, CBD hash and accessories, all within the legal framework of hemp. Happy 420!
