420 Day

What the day is

420 Day is observed on April 20, which is written 4/20 in American style. The number 420 is slang associated with cannabis, and the date has become an unofficial occasion for gatherings, rallies and discussion about cannabis laws and culture. It is not an official holiday of any government or organization.

Cannabis remains a controversial subject, and attitudes differ widely by place, age and personal experience. This page describes where the term came from and what to know about the law and health, and it does not encourage anyone to use any substance.

Origin and background

The best-documented explanation of the number involves a group of students at San Rafael High School in California. In 1971 a group who called themselves the Waldos, because they hung out by a wall, planned to meet at 4:20 in the afternoon by a statue of the scientist Louis Pasteur on campus to search for an abandoned cannabis crop they had heard about. The time became their shorthand, and the phrase spread through a circle of friends with ties to the band the Grateful Dead. It reached a wider audience when the magazine High Times began to use it in the 1990s, and April 20 became the date for public events.

Other origin stories, involving police codes or the number of chemicals in the plant, are not supported by evidence.

The legal picture is complicated and changing. Many states in the United States have legalized cannabis for adult use or for medical use, usually with an age limit of twenty-one for recreational purchases, while it remains illegal under federal law, where it has long been a Schedule I controlled substance, and federal officials have reviewed that classification. Laws in other countries differ widely. Driving while impaired is illegal everywhere, and researchers note that cannabis carries health risks, particularly for teenagers and young adults whose brains are still developing.

How to take part

• Read about the San Rafael students and how the term spread, which is a good example of how slang travels.
• Learn what the law says where you live, which can differ between a state, a city and a country.
• Look at nonpartisan summaries of the research on health and policy, and read both the arguments for reform and the concerns about it.
• If you or someone you know is struggling with substance use, the SAMHSA National Helpline offers free, confidential help at 1-800-662-4357.
• Never drive or operate machinery while impaired, and keep any cannabis products away from children and pets.