420 has become a worldwide code-name for cannabis . Fun fact: The terminology was started by a group of high schoolers who called themselves the Waldos in the ‘70s. They were trying to find a mythical field of pot and would meet at 4:20 pm everyday after school to resume their search. You can listen to the story on this episode of one of my favorite podcasts, Criminal . They never found it, but they founded a term that is used by stoners all around the world. As such, April 20th has become Weed Day.