420 started as a time of day, not a date. In 1971, five high school friends in San Rafael, California, agreed to meet at 4:20 p.m., and the number slowly became shorthand for cannabis worldwide. Here is what the record shows, which popular stories fall apart, and how April 20 became a day on the Canadian calendar.
What does 420 mean?
420 means cannabis, and more specifically the habit of using it at 4:20 in the afternoon or on April 20 (4/20 in North American date style). People say "it's 4:20" the way others say "it's five o'clock somewhere". It is slang, not a legal or scientific term, and it appears in no regulation.
The number began as a meeting time inside one group of friends. It spread outward through music scenes and magazines until it became the best-known piece of cannabis slang. For other terms you may run into, see our weed slang glossary.
Who invented 420? The Waldos story
The account is consistent across reputable coverage. In 1971, five San Rafael High School friends who called themselves the Waldos met at 4:20 p.m. by the school's Louis Pasteur statue. The time suited their day, since classes and sports practice were done by then.
Reports describe the original errand as a hunt for a cannabis patch from a hand-drawn map. They never found it, but the code (first something like "4:20 Louie", then just "420") stuck as their word for meeting up to smoke. Time, the Huffington Post and the Associated Press have all told this version.
The word then travelled. Reddix's family connection to the Grateful Dead's Phil Lesh brought the group into the band's circle, and Deadheads carried the phrase around the country. Phil Lesh is reported to have confirmed the connection in a Huffington Post interview.
| Detail | What is reported |
|---|---|
| Who | Five students at San Rafael High School: Steve Capper, Dave Reddix, Jeffrey Noel, Larry Schwartz and Mark Gravich |
| Name | They called themselves the Waldos, after the wall outside the school where they hung out |
| When | 1971 |
| Where | The Louis Pasteur statue on the school grounds |
| What | A 4:20 p.m. meeting to search for an abandoned cannabis crop, using a hand-drawn map |
| Spread | Through the Grateful Dead's circle, where Reddix's brother knew bassist Phil Lesh |
What evidence supports the Waldos' claim?
The Waldos kept their own paper trail: postmarked letters and other 1970s items that use "420", which NBC reports they store in a bank vault. According to the same report, the Oxford English Dictionary added the term in 2017 and cited some of these documents among the earliest recorded uses.
The print history is also documented. A cannabis magazine ran the first mention of 4:20 smoking and a 4/20 holiday in May 1991, and Time reports the magazine recognized the Waldos as the inventors in 1998. A popular legend says Deadheads handed out flyers in Oakland on December 28, 1990 inviting people to smoke at 4:20 on April 20, and that one reached a magazine writer. Time calls that a legend, not proof.
Be fair to the uncertainty. A different San Rafael group has said it used the term earlier, and one outlet dates the Waldos' start to 1970, not 1971. The Waldos' account is the best documented, not the only claim ever made.
What are the myths about the origin of 420?
The police-code story is the most common, and it traces to a 1991 magazine error. Nobody has produced a police code, a statute or a dispatch record that matches. The origin stories that stand up all lead back to the Waldos.
Coincidences make myths easy to invent. April 20 also happens to fall on other anniversaries, which is the only reason that one gets repeated. A date matching an event does not mean the event created the term.
| Myth | What the record says |
|---|---|
| 420 is a police or penal code for cannabis use | No police code is documented. The claim appeared in a 1991 cannabis magazine article, which attributed it wrongly |
| It is a California law number | California's Senate Bill 420 came decades later and was reportedly named after the term, not the other way around |
| Cannabis has 420 chemical compounds | No source links the term to a compound count, and published counts vary with how compounds are tallied |
| It marks Hitler's birthday | April 20 is his birthday, but Time and other coverage say this plays no part in the origin |
Why is April 20 the day, and what happens on it?
April 20 is 4/20 written as a date, and the number was already in circulation as a time. Once magazine coverage and Deadhead flyers tied the number to April 20 in the early 1990s, the date became an annual reason for gatherings, sales and rallies.
Today the day is part commemoration, part protest history and part retail event. Rules still apply: in Canada you must be of legal age, public possession is capped at 30 g of dried cannabis, and impaired driving is a criminal offence. Planning a safe ride matters more than the date.
How did 4/20 become a day in Canada?
CBC reports that the first day-long 4/20 rally in Vancouver took place in 1995, with rallies held every year since. Vancouver gatherings have been a fixture ever since, and in 2016 the event was reported moving from the Vancouver Art Gallery to Sunset Beach.
Ottawa has its own history. Crowds have gathered on Parliament Hill on April 20 for years: the RCMP estimated nearly 6,000 people in 2012, and police estimated about 2,000 in 2014. Canadian Press described the 2018 rally as the last before legalization.
That legalization came with the Cannabis Act on October 17, 2018. Since then the day has shifted from a protest to a mostly commercial and social occasion, though gatherings still happen. For anything you buy, the label is what counts, as explained in reading cannabis labels.
New to the vocabulary or the products? Start with weed measurements for what a gram, an eighth and an ounce look like, indica vs sativa for what the labels mean, and how long a high lasts before trying something new.
Sources: time.com, huffingtonpost.com, nbclosangeles.com, en.wikipedia.org, amp.cbc.ca, straight.com, laws-lois.justice.gc.ca