713 is the drinking equivelant to 420. People that smoke weed always celebrate there drug by going overboard on April, 20. Now drinkers have the same type of day on July 13th of every year.
Many people throw a 713 party, and they start drinking at 7:13PM.
"Hey, man are you coming over for 713? Bring alot of beer, we're going to need it."