Have you heard the story about how “420” became slang for using marijuana because it was the police department’s radio code for calling in a marijuana-related violation? You’re not alone. But it’s also wrong.

Other wrong answers are that the term is derived from the number of chemical compounds in marijuana, the Grateful Dead’s preferred hotel room during tours, or the death date of Janis Joplin, Bob Marley or Jimi Hendrix.

So how did 420 become the universal code for getting high, and why is April 20 seen as a fortuitous time to use marijuana? In reality, you can probably thank a group of high school students from California, according to Time magazine.

The original use of the term 420 didn’t actually refer to April 20. Instead, it referred to the time of day that a small group of San Rafael High School teenagers would congregate on campus next to a statue of chemist Louis Pasteur to smoke together. By that time, school was out and after-school activities had ended, so the group chose to engage in another extracurricular activity: using marijuana.

The year was 1971, and the five students would simply tell each other “420” to communicate that they’d be meeting up to smoke marijuana that day.

There is an important link to the Grateful Dead, too: San Rafael High School is located in California’s Marin County, where the band got its start. At one point, Dave Reddix, from the original group of San Rafael students, became a roadie for Grateful Dead bassist Phil Lesh and is thought to be responsible for spreading the term to Deadheads in the area.

Slowly but surely, it must have caught on. In 1990 — almost 20 years after the high school group coined the term to describe their afternoon gathering — a group of Deadheads put out a flyer inviting people to meet “at 4:20 on 4/20 for 420-ing” at a particular spot in Marin County.

The flyer, however, contained an incorrect piece of information. It said that the use of the term 420 “started as the police code for Marijuana Smoking in Progress.” It’s unclear whether the organizers were misinformed or simply wanted to create a better backstory.

Steven Bloom, who at the time was a reporter for High Times magazine, published the flyer, with its incorrect backstory and all. So, while the high school friends can take credit for inventing the term, the Deadhead network and Bloom can reasonably claim responsibility for its popularity and for the perception that the term came from the police code.

Today, 420 is too popular and widespread to be of much use to anyone who wants to be secretive about using marijuana. However, with the legalization of marijuana in the state of California, there’s really no need for a code word anyway.

Even so, 420 remains an integral part of cannabis culture. Many cannabis users simply appreciate that partaking on April 20 or on any day at 4:20 p.m. can be a fun way to enjoy a feeling of celebration and solidarity with other marijuana enthusiasts.

Many of California’s legal cannabis dispensaries pay homage to the folklore in different ways. HPC Port Hueneme, for example, included the code in its website address, The dispensary also commonly offers in-store specials that start at 4:20 p.m., giving a shoutout to the significance of the time and providing a great way to celebrate.

Even the California Senate gave a sly nod to the number by passing its Medical Marijuana Program Act as California Senate Bill 420.

With April 20 just around the corner, keep an eye out for many ways to celebrate. After all, now that California is in its third year of legal cannabis sales, its residents are getting to be experts.

For more information about HPC Port Hueneme and any upcoming specials, visit

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Written by Jessica Levy, for HPC Port Hueneme

These products are not intended to prevent, treat, diagnose or cure any condition or disease. Recreational/medical marijuana is available under California law however it is illegal under Federal Law. Not intended for use by anyone under 21.

Members of the editorial and news staff of the USA TODAY Network were not involved in the creation of this content.

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