Where did the term 420 originate from?
The term started in 1971 at San Rafael High School (San Rafael is north of San Francisco) by a group of students that used to get high after school – at 4:20. I went to San Rafael High in the late 70’s early 80’s and can attest to the fact that this was in common usage by the kids that were into that sort of thing (as I was at the time) and it just spread and spread. It has NOTHING to do with police codes.