The expression 420, 4:20, or 4/20 (“four-twenty” or “four-twenty”) is a code word that has become common worldwide and stands for the consumption of cannabis. There is no real meaning in the proper sense. The numerical code is seen more as a universal topic and is generally used in connection with cannabis culture. Whether it’s growing hemp plants, baking marijuana cookies, or smoking a joint, you will find everything related to cannabis and its consumption with the code word 420.

Term origin

There are a lot of myths surrounding the origin of the number 420. Some notable ones are listed below.


  • There are 420 chemical compounds found in cannabis.
    (Although believed to be more than 500).
  • 420 is a police code related to cannabis.
    (However, this is not the case, as police code 420 refers, in criminal terms, to blocking public property.)
  • April 20th is the best day to plant cannabis.
    (Of course, this varies from region to region and depends on many different factors.)
  • Bob Marley passed away on April 20th.
    (But his actual date of death is May 11th, 1981).

Actual Origin

However, the actual origin of 420 you can find in 1971. It was 4:20 p.m. for a group of San Rafael High School students to meet to search for an alleged existence of a hemp plantation. Later this became the meeting place to enjoy cannabis. They called themselves “The Waldos.”

However, the numerical code was initially only a Californian phenomenon. But when the band “Grateful Dead” became aware of 420 and took over the code, they were the ones who were decisive in the development. First, the term was widely used in the musician and stoner scene; later, when an editor from the New York magazine “High Times” reported on it, it first conquered the USA and eventually became the common code word for cannabis worldwide.


The code was also eventually carried over to a specific date: April 20th. The American spelling for this is 4-20, considered a holiday in the smoking scene.

For example, on April 20th, 1995, the Cannabis Action Network hosted one of the earliest annual events related to 420 at Maritime Hall in San Francisco, California. This event always takes place between 4:20 p.m. and 4:20 a.m. Since then, dozens of other locations across North America are strives to keep celebrating cannabis culture alive. It extends well beyond North America. On this day, events and festivals around the world revolve around the topic of cannabis.


Various popular movies, series, and television shows referenced the term 420. For example, in the film “Fast Times at Ridgemont High,” the final score of a football game is shown as 42-0. Or, in Quentin Tarantino’s “Pulp Fiction,” most of the clocks are set to 4:20. There are also scenes in The Simpsons where you can see the numbers.

On April 20th, 2000, a San Francisco magazine published an article detailing the various myths surrounding the creation of 420. The San Rafael High School student group, “The Waldos,” was credited with coining the number code.

The website of the US Department of Health and Human Services’s Center for Addiction Prevention published a document in 2001 entitled “It’s 4:20 – Do You Know Where Your Teenager Is?”

In 2004, the Governor of California signed California Senate Law 420, which regulates the use of marijuana for medicinal purposes. Most likely because of the existing thematic connection.

With the decriminalization and legalization of marijuana, many shops, record companies, and radio stations have adopted the term as part of their branding, including Atlanta Sweetwater Brewing Co. 420 Pale Ale or 420 Tours (low-cost travel packages to the Netherlands and Jamaica), Highway 420 Radio, as well as record companies and music acts.