The origin of 4/20 Weed Day

By Madeline Holcombe

Published April 20, 2020

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April 20, or 4/20, is known as "Weed Day" in some circles because the date corresponds with a numerical code for marijuana.

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So how did the number 420 come to represent smoking pot? Let's get the myths and rumors out of the way.


The legend of the California penal code

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Some claim the number is drawn from the California criminal codes used to punish the use or distribution of marijuana. The state's 420 code actually applies to obstructing entry on public land. But the rumor sounds a lot like …


The legend of the police radio code

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Neither the LAPD nor NYPD even have a code 420. San Francisco Police have one, but it's for a "juvenile disturbance." So never mind that theory.


The legend of the Dylan song

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This one is a nod to Bob Dylan's song, "Rainy Day Women #12 & 35" and its lyric, "Everybody must get stoned." Multiply 12 by 35 and you get 420. Seems a bit of a stretch, though. The story that seems most likely is …

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The legend of the Waldos

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Chris Conrad, curator of the Oaksterdam Cannabis Museum in Oakland, California, says 420 started as a secret code among a group of friends at San Rafael High School in the early 1970s who called themselves "the Waldos."


They would often meet at 4:20 p.m. to get high. Their code gradually spread — possibly via Grateful Dead followers — across California and beyond. It's even the number of a California Senate bill that established the state's medial marijuana program.

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420 can now be seen on T-shirts and throughout pop culture. And of course, on the calendar every April.