4/20, the unofficial marijuana holiday, is observed by millions across the globe on April 20th every year. As pot smokers get ready with their bag of chips, beverages and their favourite television shows, many still do not know the significance of 420.

The day is marked by a flurry of rallies, specifically in the United States, where people gather and enjoy legal and recreational marijuana. Such rallies are largely observed in states like California and Colorado.

Also Read: Marijuana’s recreational use gets US states high on cash

While there is no “official” reason why 4/20 is celebrated around the world, there are multiple theories that pot smokers consider to be true. 

The leading theory is, shared by cannabis activist Steven Hager, is that a group of California students in late 1970s ritualistically gathered at 4:20 PM and smoked marijuana. The gathering slowly snowballed and became a tradition, spreading across the United States.

Another theory, as reported by Vox, suggested that marijuana contained 420 active chemical compounds, directly connecting it to the date April 20. However, this was later disproved after scientists confirmed there are about 500 such compounds in marijuana. 

Cannabis legalisation activists say that April 20 is now seen as a counterculture event that challenges social, cultural and legal stigmas linked to the consumption of marijuana. 

Keith Humphreys, a drug policy expert at Stanford University, told Vox, “If a corporate marijuana industry adopts 4/20, it would still be a celebrated event, but not with the same counter-cultural meaning.”

Also Read: Less crime and more weed: New York City’s plan to revive economy

Humphreys added, “People celebrated Christmas long before it became an occasion for an orgy of gift-buying and materialist consumption, but the meaning of the holiday for most people was different then than it is now.”

So far, 18 states in America have legalised the use of cannabis, medical and recreational. These include Colorado, New York, Illinois, Connecticut, Oregon, New Jersey and others.