What is 420? 420 Meaning and the History Behind Weed

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

Yes, it seems arbitrary. So how did the number 420 come to represent smoking pot?

First, let’s get the myths and rumors out of the way:

Everybody knows 4:20 is the time to smoke pot. And everybody knows 4/20 is the international pot-smoking day. But not many people, not even the oldest and most ardent pot smokers, knows why or how the number 420 became linked to pot smoking.

There are a few old tales which describe how this national holiday, and that special time of the day, became so iconic. Here’s everything we know about how 4/20 became more than a mid-April day.

The legend of the California penal code

Some claim the number is drawn from the California criminal codes used to punish the use or distribution of marijuana. But the state’s 420 code actually applies to obstructing entry on public land. So, not quite.

But the rumor sounds a lot like …

The legend of the police radio code

Neither 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.

Then there’s …

The legend of the Dylan song

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. And Dylan himself has never confirmed any link.

The story that appears to hold the most water is …

The legend of the Waldos

According to Chris Conrad, curator of the Oaksterdam Cannabis Museum in Oakland, California, 420 started as a secret code among high schoolers in the early 1970s.

A group of friends at San Rafael High School in Marin County, California, who called themselves “the Waldos,” would often meet at 4:20 p.m. to get high.

For them, it was an ideal time: They were out of school but their parents still weren’t home, giving them a window of unsupervised freedom. They met at that time every day near a statue of Louis Pasteur, the scientist who pioneered pasteurization.

And Then There Are Just Some Batshit Ideas

The remaining theories around 420 are so wild we might as well not even go into detail. Some think it’s named after the day Bob Marley died, but he died on May 11. Some think it has something to do with Adolf Hitler’s birthday, but why the hell would that mean anything? (Even if it is his birthday.) Lastly, some stoned-off-their-ass person once said April 20 is the best day to plant marijuana, but that very clearly depends on where you’re planting it.

In the end, the only real way to trace it back is to those ambitious high school kids in San Rafael. They toked so we could rip. They lied to their parents so we could have an excuse once a day—and especially on April 20—to pull out all the stops and get as high as the lord above us.