The term was coined from a group of teenagers at San Rafael High School in San Rafael, California, United States in 1971.[2][3] The teens would meet after school at 4:20 p.m. to smoke marijuana outside the school.

Known 420 Myths

Police dispatch code for smoking pot is 420.
The number 420 is not police radio code for anything, anywhere. Checks of criminal codes suggest that the origin is neither Californian nor federal. For instance, California Penal Code 420 defines as a misdemeanor the hindrance of use of public lands.

There are approximately 420 active chemicals in marijuana.
Actually, there are approximately 315 active chemicals in marijuana. This number goes up and down depending on which plant is used.

April 20th is National Pot Smokers Day.
Well, it is now ; but that wasn't the origin.

April 20th is Hitler's birthday.
Yes, it is his birthday. But, as 420 started out as a time, not a date, his birthday had nothing to do with it.

The date of the Columbine school shootings.
This happened after the term was already in use.

4:20 is tea time for pot-smokers in Holland.
Tea time in Holland is at 5:30 pm, or is it 2:30 pm? Seems no one is quite sure when the wonderful people of Holland drink their tea.

Det startede i Californien på en High School, de fik så fri kl fire og havde lige tyve minutter til at rulle sig en joint. De fyrede så op 420 hvis du forstår

http://en.wikipedia.org/wiki/420_%28cannabis_culture%29

Du må sgu finde en mere saglig kilde end wikipedia. Wikipedia beviser ikke en skid. Man kan rette som man har lyst i de artikler. Har f.eks. selv lavet en side på wikipedia som fortalte at en af mine venner var det såkaldte "missing link" i Darwins evolutions teori.