It was slang when I worked foodservice jobs in a college town on the 
east coast in the late 1980s. It indicated a good or appropriate time 
to smoke marijuana on any given day. If one had been sober that long, 
one had presumably worked a full day and discharged one's work or 
school duties industriously.

When bartending in Iowa City, I had a few regulars who would not 
drink until 5pm. If they got off work early, they might sit nervously 
for fifteen or twenty minutes. They thought they were drinking 
responsibly. They were above reproach; they had no problem with 
alcohol consumption because they waited, every day, until 5pm for the 
first drink. One person waited not for 5pm but for Tom Brokaw to 
appear on the television.

As for "420," I most often heard the term in the expression, "It's 
4:20 somewhere."

Jon

>My undergraduate students say 420 is marijuana slang, originating in 
>California, that originally announced that a group would smoke a 
>joint at 4:20.  Anybody with clearer information?


-- 
Jon Miller, Asst. Prof. of English, Dept. of English, Univ. of Akron, 
Akron, OH 44326-1906. office and voice mail, 1-330-972-5717.