Today my 10:00 class had a lot of absences. When I asked my students if something was going on, one replied that maybe people were wasted from yesterday. Why yesterday I asked? The reply came: "420". What's that? A student explained that 4/20 was a day to smoke pot and that it also had some connection with Columbine and was some sort of police code when they were going to make a bust.
Well the truth is a bit less interesting. According to www.snopes.com, (http://www.snopes.com/language/stories/420.htm), the authority on urban legends and slang, "420" began among a group of high schoolers to signify the time of day when they could light up...and I don't mean cigs either. Somehow this spread and the meaning shifted to the date April 20 rather than 4:20 pm aided by an unfortunate set of coincidences; for instance 4/20 is the birth day of Hitler and yes it was the day of the Columbine massacre.
All the other baggage supposedly related to 420- that is some sort of police code is not true. Oh yes Albert Hofmann took his first intentional LSD trip at 4:20 on 19 April 1943, having previously accidently taking LSD isolated from the fungus that produced it.
So have a nice 420 tommorrow, whatever your trip.
A Conversation with Albert Hoffmann http://www.maps.org/news-letters/v08n3/08330hof.html
NIDA Infofacts: LSD(http://www.nida.nih.gov/Infofacts/LSD.html) You trust the government right?