The favorite day of stoners across the globe is upon us: April 20 or 4/20, also known as weed day, is this Saturday.

Coincidentally falling on the same weekend as National Cold Brew Day and National Record Store Day, Saturday is shaping up to be something of a paradise for weed, coffee and music fans alike.

But how did an otherwise random day in April somehow become the mecca of marijuana enjoyment? Many theories have swirled over the years. While more exciting ones harken the holiday back to police busts or hidden messages in classic songs, the widely accepted origin is a little more reminiscent of a classic high school experience.

How did 4/20 become the official unofficial weed holiday? Here's what we know.

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What does 420 mean?

420 refers to the day 4/20, or April 20. The date has come to be known as the official stoner holiday on which marijuana smokers celebrate their love of bud.

The number 420 itself has also come to be associated with marijuana and smoking and is often used as a colloquial term for the flower and the act of consuming it.

Smokers see 4/20 not only as a day to kick back and celebrate their love of the stuff, but also to push for broader legalization and decriminalization of marijuana federally in the U.S. and beyond.

Where is weed legal?The states where recreational, medicinal marijuana is allowed in 2024

Why is 420 associated with weed?

You may have heard some of the most popular rumors that have circled the cultural zeitgeist over the years: that 420 is the code police used to describe marijuana smoking; 420 is the number of active chemicals in weed that get you high; April 20 was Bob Marley's birthday (it wasn't); that it's a reference to Bob Dylan’s song “Rainy Day Women #12 & 35” (12 times 35 equals 420).

In reality, it's much simpler and perhaps less exciting than any of that.

While no one can say for certain, one widely accepted origin traces back to a group of teenagers hanging out after school.

In the early '70s, five students at San Rafael High School in Marin County, California would meet outside of the school after extracurricular activities had ended for the day. The group, eventually called the "Waldos," simply for the fact they met by a wall to do their thing, made their official meeting time 4:20 p.m. and eventually started using 420 as code for smoking.

One of the Waldo members, Dave Reddix, later got work as a roadie for the Grateful Dead, and the band helped to popularize the term, he told Time. Specifically, a flyer distributed by a group of Oakland Deadheads in December 1990 inviting people to smoke on April 20 at 4:20 p.m. did the trick.

A reporter at High Times magazine got hold of the flier and printed it in 1991, bringing it to the attention of cannabis fans across state lines. The magazine continued to use the term in future publications, solidifying its place in popular vernacular.

Steve Bloom, the "High Times" reporter who originally received the flyer, later credited the Waldos for originating the term, saying in a 2013 blog, "...they wanted people all over the world to get together on one day each year and collectively smoke pot at the same time. They birthed the idea of a stoner holiday, which April 20 has become."

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Where is weed legal?

Looking forward to partaking this 4/20? Make sure you know the laws in your area before you do.

The legalization of marijuana has been a long state-by-state process, and various levels of use from none to medical to recreational are allowed in jurisdictions across the U.S. At least 25 have fully legalized recreational use, and more are either in the process or have future voting on the books.

Wondering about the status in your state? Check our list of where recreational, medicinal marijuana is allowed in 2024.