Cannabis Holidays Calendar: 4/20, 7/10, Green Wednesday and Pi Day

By James Buddsey · Updated October 30, 2026

The main cannabis holidays are 4/20 (April 20), the biggest day on the calendar; 7/10 (July 10), “Dab Day,” because 710 upside down spells OIL; and Green Wednesday, the day before Thanksgiving, which falls on November 25 in 2026. Pi Day (March 14) is not a real cannabis holiday, but it earned a place in stoner math because 3.14 rounds into a joke: 3.0 times 14.0 equals 42.0.

This page started in 2016 as a 187-word gag about Pi Day as 4/20’s “younger cousin.” The math still checks out, and we kept the joke, but we have built it into a full calendar of cannabis holidays: where each one came from, when it falls in 2026 and 2027, and how to celebrate without getting into legal trouble. Dates are as of October 27, 2026.

Cannabis holidays calendar at a glance

Thanksgiving is the fourth Thursday of November, which puts it on November 26 in 2026 per the U.S. Office of Personnel Management’s federal holiday list and November 25 in 2027, so Green Wednesday moves each year.

Why is 4/20 the weed holiday?

4/20 traces back to five San Rafael High School students, known as the Waldos, who in fall 1971 met at 4:20 p.m. by a Louis Pasteur statue to search for an abandoned cannabis patch; “4:20” became their code word and spread through Grateful Dead circles and High Times. The Waldos’ own account is at 420waldos.com, and Time traces how a December 1990 flyer handed out at a Grateful Dead show in Oakland led to a 1991 High Times article that took the term national. The popular myth that 420 is a police radio code is false. Our full story is Where Did 420 Come From?

From a code word it grew into a day of rallies and smoke-outs. Boulder‘s University of Colorado gathering drew about 10,000 people in 2008, and the number became so famous that Colorado replaced its Mile 420 highway sign with “Mile 419.99” to stop thefts. Today it is also a major retail event, with dispensary deals and events across legal states.

What is 7/10 (Dab Day)?

7/10 is the concentrate holiday: flip “710” upside down and it reads “OIL,” so July 10 celebrates cannabis oils, wax, shatter, rosin and other extracts usually consumed by dabbing. The wordplay is clear, but its exact start is not. Weedmaps says early adopters on forums such as TokeCity and Urban Dictionary started using the term around 2011 for oil-based products, and that some sources credit TaskRok of Highly Educated with popularizing it, but it calls the origins “a little hazy,” so treat any single founding story with caution. Dispensaries now run concentrate sales on July 10 much like 4/20 flower deals.

Dabs are far more potent than flower, so 7/10 is a day to go slow if you are new. Our guides to weed dabbing and dab pens explain how they work and the risks.

What is Green Wednesday?

Green Wednesday is the cannabis industry’s name for the day before Thanksgiving, when shoppers stock up before family gatherings and four-day weekends; it has become a major sales day. Cannabis data firm Headset reported Green Wednesday sales up 33% over an average Wednesday in 2021, and growth of 48% in 2022 and 52% in 2023 (Headset, November 2024). The name plays on Black Friday, and retailers were already promoting it by 2018, as CNBC reported in 2018. In 2026 Green Wednesday is November 25; our November and December events calendar lists what else is happening around it.

Is Pi Day a weed holiday?

Not really, but it is a good joke: March 14 is 3/14, and 3.0 times 14.0 equals 42.0, which is close enough to 420 for anyone who has been celebrating. Pi Day itself is a math holiday. The U.S. House even passed a nonbinding resolution supporting “the designation of a ‘Pi Day'” on March 12, 2009, by a vote of 391 to 10. Our original 2016 advice still stands, minus skipping work: get some friends, some green where it is legal, and some pie. Edibles count, but start low, since a slice of infused pie can be far stronger than it tastes.

Are there other cannabis holidays?

Yes, smaller ones come and go, but 4/20, 7/10 and Green Wednesday are the three that dispensaries and brands most widely treat as holidays. Many legal states also have their own anniversaries, such as the day stores opened. Colorado’s first adult-use stores opened on January 1, 2014, the New York Times reported, which makes New Year’s Day a quiet second holiday there. Industry events add their own dates: MJBizCon in Las Vegas runs December 1 to 4, 2026, and is a trade show for people 18 and older, not a consumer party.

How to celebrate cannabis holidays legally

• Be 21 or older and stay in a legal state. Check our state law guides for limits.
• Buy from licensed stores. Holiday deals draw crowds; bring valid ID and cash, and know your state’s purchase limit.
• Don’t use in public. Nearly every legal state bans public consumption, and parks and sidewalks are not exceptions on 4/20.
• Stay off federal land. National parks and forests ban possession under federal rules, even in legal states.
• Never drive high. Plan a ride before the party starts.
• Don’t cross state lines. Taking cannabis from one state to another is a federal crime.

What this means for you

Mark April 20, July 10 and the Wednesday before Thanksgiving if you want the best dispensary deals, and expect lines on all three. Plan ahead: check your state’s purchase limit, shop early in the day, bring ID, and arrange a ride home. Pi Day is optional, but the pie is not. Find a licensed store near you in our dispensary directory.

Cannabis Holidays FAQ

Dates as of October 27, 2026. Cannabis is legal only for adults 21 and older in states that allow it, and remains illegal under federal law for adult use. General information, not legal advice.