Skip to main content Why Pi Day is one of the biggest days of the year for an SF pizza-and-beer mainstay FacebookTwitterEmail 1of20 Pi Bar owners Jen Garris (left) and Rich Rosen behind the bar at their restaurant in San Francisco, Calif. on March 12, 2021.Douglas Zimmerman/SFGATEShow MoreShow Less 2of20 Pi Bar owners Jen Garris (left) and Rich Rosen behind the bar at their restaurant in San Francisco, Calif. on March 12, 2021.Douglas Zimmerman/SFGATEShow MoreShow Less 3of20 4of20 Co-owner Rich Rosen stands at the doorway of his restaurant, the Pi Bar, in San Francisco, Calif. on March 12, 2021.Douglas Zimmerman/SFGATEShow MoreShow Less