420 is a part of cannabis lore. It can be used to refer to the drug. It can be used to refer to cannabis appreciation. It can be used to refer to a time - 4:20 - time for a toke. It can be used to refer to a day – April 20 – known as cannabis appreciation day.
Cannabis lore, almost by definition has a ring if not feel of the secret to it. This is because of cannabis’ underground, illegal status for most of the past century. Now, as the drug is legitimized, its culture and language are becoming mainstream.
But where does this piece of slang come from? And how should you use the term today?
4/20 is not either Bob Marley’s birthday or date of death. It was the room number that The Grateful Dead asked for when they toured. But they did not always. It is Hitler’s birthday too, but that has been forgotten to history books. It is also not the California police radio code for a pot bust. But it is the radio code for a homicide in both Las Vegas and in fiction.
SB420 was also the number assigned to the California State bill which started the Medical Marijuana Program Act which established guidelines for Prop 215.
However, according to “real” stoner history, these are all false rumors about the term's origin. According to them, the term comes from 1970’s California. A group of cannabis enthusiasts at San Rafael High School used it as code. They met at 4:20 every afternoon in a designated location to smoke. The “Waldos” as they became known, also went in search of a supposed hidden cannabis crop with a “treasure map” given to them by the grower.
However true (or not) this lore is, the use of the term proved popular. It began to spread. Nobody is entirely sure how or why. It could have been the presence of The Grateful Dead. It could have been the hippie culture of the time.
Bottom line? 420 in popular culture usually refers, in some way, to cannabis. That is ultimately, all you need to know.