Where Does '420' Come From? The True Story of Pot's Favorite Number

Every stoner has today marked on their calendar as marijuana's sacred holiday. Over the decades, 4/20 has become something of a nationally known day that people celebrate by getting high. It's like a St. Patrick's Day for smoking weed—but many regular weed consumers may not know the day's origins. (Or maybe they're just too high to remember.)

Theories have circulated for years—including that it's a police code for marijuana or that there's some connection to Adolf Hitler's birthday—but the name is usually attributed to exactly who you'd expect: high school students who wanted to toke up after school.

According to a December 1998 issue of High Times, Steve Capper and four of his friends, who called themselves "the Waldos," used the term when they were students at California's San Rafael High School in the 1970s. The group, who were mostly interested in the Marx brothers and standup comedy besides pot, would sit on a wall and mock greasers and cheerleaders outside their school while smoking weed.

Since school let out at 3:10 p.m. and some had after-school activities that would last about an hour, they scheduled 4:20 as their regular time to meet near a Louis Pasteur statue outside the school. Throughout the day, they'd whisper "420" to each other to remind that they had plans after school.

A recreational marijuana smoker indulges in smoking weed on April 14, 2020 in the Bushwick section of the Brooklyn borough of New York City. Bruce Bennett/Getty

"We did discover that we could talk about getting high in front of our parents without them knowing by using '420,'" Capper told High Times.

The group credited their fandom for Grateful Dead-offshoot New Riders of the Purple Sage as a possible source for the term getting picked up by Deadheads and spreading. In 2017, Time reported that one Waldo Dave Reddix was hired by Dead bassist Phil Lesh, which also helped the term catch on for Deadheads. HuffPost also referenced a flyer, which was later published in High Times, that was distributed at a Dead show in 1990; it encouraged people to "meet at 4:20 on 4/20 for 420-ing" in Marin County, California.

High Times later began capitalizing on the term, using it regularly in their marketing, even purchasing the 420.com domain in the '90s. "I started doing all these big events—the World Hemp Expo Extravaganza and the Cannabis Cup—and we built everything around 420. The publicity that High Times gave it is what made it an international thing. Until then, it was relatively confined to the Grateful Dead subculture. But we blew it out into an international phenomenon," High Times editor Steve Hager told HuffPost in 2010.

Capper, meanwhile, told Time that it's been funny to see the name they created in high school pop up from time to time in pop culture, and that he hopes their slang makes people feel like they're part of the same "brotherhood of outlaws," that the Waldos felt like they were in their teen years. But he also said that he's glad marijuana is becoming legal in more places.

"It's cool that it's legal, and people aren't going to jail as much," he told Time. "Now legalization is happening so fast, you've got to stand back and go, 'This is weird.'"