How Did '4/20' Become
a Holiday for Weed?.
One common theory is that it stems
from a California criminal code for
those who distribute the drug.
According to CNN, California's 420 code is actually for obstructing entry on public land.
The state's medical marijuana
program was created from a bill
with the number 420.
Oaksterdam Cannabis Museum's Chris Conrad
says "4/20" started as a code in
Marin County, California, at San Rafael High School.
In the 1970s, a group called
"The Waldos" would get together at
4:20 PM to smoke pot.
The time of the day was convenient as it
was right after school ended with
no parental supervision just yet.
"4/20" became a code word that allowed
them to notify each other in front of
unsuspecting parents.
From there, the phrase likely
spread across the country