If you have to ask what 4/20 Day is, there's a good chance you're not a regular marijuana user.
In the slogan and image steeped world of pot users, those three numbers have special significance.
It's not clear why, according to most web based accounts, but April 20th has evolved into a counterculture holiday in North America. It's a day where people gather to celebrate and consume cannabis.
Local news from across Southern California
Explanations range from state penal codes, to a time of day when smokers prefer to light up.
In any event, the 20th day of the fourth month, April 20th, has been a special day for pot users ever since the 1970s.
It's also a day where many kids may try drugs.
Some parents are using the day as an opportunity to talk with their kids about drugs.
"Being able to educate them in the signs that they can look for," says Jonathan Harper, Emergency Medical Technician.
Harper's ambulance company is working with an Arizona based non-profit called NotMYkid.Org.
In several counties on Friday the distributed home drug testing kits, a $40 value for free.
On 4/20 day Harper says he has a unique perspective on marijuana use. He says it's a gateway drug to harder substances, and in his job he's seen hundreds of overdoses.
"You trust your kid, that he's going to tell you the grades that he's getting in school," says Harper, "but as a parent you're still going to check that report card when it shows up in the mail."