This is an accepted version of this page 420, 4:20 or 4/20 (pronounced four-twenty) is cannabis culture slang for marijuana and hashish consumption, especially smoking around the time 4:20 p.m. (16:20).

[3][4] Five high school students in San Rafael, California,[5][6] coined the term as part of their 1971 search for an abandoned cannabis crop, based on a treasure map made by the grower.

[7][8] Calling themselves the Waldos,[9][10] because their typical hang-out spot "was a wall outside the school",[11] the five students—Steve Capper, Dave Reddix, Jeffrey Noel, Larry Schwartz, and Mark Gravich[12]—designated the Louis Pasteur statue[13] on the grounds of San Rafael High School as their meeting place, and 4:20 p.m. as their meeting time.

After several failed attempts to find the crop, the group eventually shortened their phrase to "4:20", which ultimately evolved into a code-word the teens used to refer to consuming cannabis.

[70][71] In Northern Cyprus, known for strict drug laws and intolerance to cannabis consumption,[72] the first 420 event was held in the capital city Lefkoşa in 2015.

On April 20, 2017, a small group of protesters carried out an event near the parliament building and made a public statement, demanding the legalization of cannabis sale, consumption, and production with state regulations.

[73] Despite two studies reporting a supposed increase in the risk of fatal motor vehicle crashes on April 20,[74][75] further investigation and analysis found the evidence did not support such claims.

[92] Following the success of Washington, D.C.'s Initiative 71 to legalize cannabis in 2014, Mayor Muriel Bowser granted license plate number 420 to the campaign's leader, Adam Eidinger.

[99] Musk purchased Twitter in 2022 at $54.20 per share and the financing documents were signed on April 20, acknowledging the reference to marijuana culture.