“4-20” (or 420) originated in the early 1970s with a group of San Rafael, California high school students known as the “Waldos.” It was originally a code for them to meet at 4:20 p.m. to smoke marijuana, which later spread globally through Grateful Dead culture to become an unofficial international cannabis holiday on April 20.
The True Origin and Meaning
The “Waldos” Initiative (1971): Five students (Steve Capper, Dave Reddix, Jeffrey Noel, Larry Schwartz, and Mark Gravich) met daily at 4:20 p.m. near a statue of Louis Pasteur at San Rafael High School to smoke marijuana before searching for a rumored abandoned cannabis crop.
Slang Development: They used the phrase “4:20 Louie” to coordinate and eventually simplified it to just “420” as a secret code for smoking weed.
Grateful Dead Link: A member of the Waldos had connections to the Grateful Dead band, allowing the term to spread among the band members and their fan base in the 1970s and 80s.
Media Popularization: High Times magazine popularized the term in the 1990s after seeing a flyer from a Grateful Dead concert referencing “420” on April 20th.
Common Misconceptions
It is not a police code for marijuana possession.
It does not refer to the number of chemicals in cannabis.
It is not based on a Bob Dylan song.
Today, 4/20 is celebrated globally as a day of cannabis advocacy, community, and commercial, with many dispensaries offering large sales, making it a “Black Friday” for the cannabis industry.