the origin of 420
actally the l.a. times did research and found out the real origin of 420
http://www.latimes.com/news/local/la-042002420.story
excerpt:
In any case, Steve said, in 1971, a friend approached them one day at school with a map of Marin County. "He said his brother-in-law was in the Coast Guard and had planted a patch of weed out on the Point Reyes Peninsula, but believed his C.O. was onto him, and he didn't want to get busted. So he had offered it to our friend, who was offering it to us."
The group agreed to meet that afternoon after school at 4:20 p.m. by a campus statue of Louis Pasteur, he said, and head out to search for the marijuana patch. "But one thing led to another," he laughed, "and suffice it to say we never found it. Every day we'd meet at 4:20 by this statue, and every day we'd just end up getting high and driving around for hours." Over time, the mere phrase "four-twenty"--exchanged in a hallway, or discreetly mentioned in the presence of teachers and parents--became their personal code for "time to get high," he said.
Steve and his friends went off to college--mostly at San Diego State and Cal State San Luis Obispo--but their secret code lived on in Marin County, preserved by younger brothers and friends. "We have postmarked letters we wrote to each other from the early '70s with all kinds of references to '420,' " Steve said. Gradually, he said, the term was picked up by local teenagers, and then by Deadheads, who are legion in Marin County.
"By the mid-1990s," he said, "we started seeing it all over. We couldn't believe it--it was on hats, T-shirts, record labels, cleaning solutions, all over the Internet."