420 Day, observed annually on April 20 (4/20 in U.S. date format), is an unofficial holiday celebrating cannabis culture, especially the consumption of marijuana. The term "420" originally referred to the time 4:20 p.m., when a group of five high school students from San Rafael, California, in the early 1970s would meet to smoke cannabis. These students, known as the Waldos, used "420" as a code word for cannabis consumption, which later evolved into a broader cultural symbol
. Over time, April 20 became a day for cannabis users, advocates, and producers to celebrate marijuana, often with public smoking events, rallies for legalization, and dispensary discounts. The day also serves as a platform for advocacy toward the legalization and decriminalization of cannabis for both medicinal and recreational use in various U.S. states and beyond
. 420 Day has grown from a small counterculture event into a widely recognized cultural phenomenon associated with cannabis acceptance and reform efforts
