Random Thoughts.....What Are You Thinking?

The earliest use of the term began among a group of teenagers in San Rafael, California in 1971.[2][3] Calling themselves the Waldos,[4] because "their chosen hang-out spot was a wall outside the school,"[5] the group first used the term in connection to a fall 1971 plan to search for an abandoned cannabis crop that they had learned about.[4][6] The Waldos designated the Louis Pasteur statue on the grounds of San Rafael High School as their meeting place, and 4:20 pm as their meeting time.[5] The Waldos referred to this plan with the phrase "4:20 Louis". Multiple failed attempts to find the crop eventually shortened their phrase to simply "4:20", which ultimately evolved into a codeword that the teens used to mean pot-smoking in general.[6]

High Times editor Steven Hager wrote "Are You Stoner Smart or Stoner Stupid?" in which he called for 4:20 pm to be the socially accepted hour of the day to consume cannabis.[7] He would go on to attribute the early spread of the phrase among Deadheads.[7]