Every year on April 20, millions of people around the world mark what has become known as 420, a date closely associated with Cannabis culture.
But while the number is widely recognized, many people still ask: what exactly does ‘420’ mean, and how did it become a global phenomenon?
The story traces back to the early 1970s in California, where a group of five high school students known as ‘the Waldos’ created what would become one of the most famous codes in pop culture.
The group (Steve Capper, Dave Reddix, Jeffrey Noel, Larry Schwartz, and Mark Gravich) would meet at 4:20 p.m. after school near a statue of chemist Louis Pasteur on their campus. The time worked perfectly, as it was after their extracurricular activities, including sports practice.
Using a hand-drawn map, the group set out to find a rumored abandoned cannabis crop near the Point Reyes Peninsula. To avoid drawing attention from teachers and parents, they used the phrase “4:20 Louie” as a secret code to coordinate their meetups.
They never actually found the hidden crop—but the code stuck.
Over time, ‘4:20 Louie’ was shortened to simply ‘420,’ which the group began using more broadly to refer to smoking cannabis.
The term might have remained a private joke if not for its unexpected link to the iconic rock band Grateful Dead.
One of the Waldos had a connection to the band’s circle. As a result, the term began circulating among the band and their fanbase, known as “Deadheads,” helping it spread across the United States.
By the early 1990s, the term gained even wider exposure when High Times magazine editor Steve Bloom came across a flyer explaining the ‘420’ story. After publishing it, the phrase quickly entered mainstream cannabis culture.
Unlike many urban legends, the origin of 420 is backed by documentation. The Waldos reportedly kept letters and school newspapers from the 1970s referencing the term, which later served as evidence of its history.
This documentation played a role in the term being formally recognized by the Oxford English Dictionary, which added ‘420’ as an entry in 2017.
As cannabis culture grew, especially through media, music, and the internet, April 20 (4/20 in U.S. date format) evolved into an unofficial holiday.
Today, 420 is marked by gatherings, festivals, and online trends in many parts of the world, particularly in countries where cannabis laws have been relaxed or legalized.
In countries like Canada, where cannabis is legal, April 20 is often celebrated openly with large public events and concerts. In contrast, in countries such as Kenya, cannabis remains illegal, meaning the day is mostly observed online or within private spaces.
Social media platforms like TikTok, Instagram, and X have also played a huge role in popularizing 420, with users sharing memes, coded messages, and lifestyle content tied to the day.
While 420 is often associated with celebration, it has also become a moment for broader conversations around cannabis ranging from legalization debates to discussions about medical use and mental health.
Globally, the cannabis industry has grown into a multi-billion-dollar sector, adding another layer of significance to the day beyond its cultural roots.
More than five decades after its origin, 420 has evolved from a simple inside joke among teenagers into a globally recognized cultural marker.
