It's an unprecedented move, mandated by state law because of the budget crisis.
The one day a month closure is scheduled to last until June of next year and will save $94.3 million.
"It's a bad thing when a fundamental aspect of government has to be reduced because of a budget," said Judge James McBride
McBride is the presiding judge of San Francisco Superior Court.
"It's going to create increased lines, increased congestion in our courts. It'll increase delay and resolution of cases," said Judge McBride.
California Chief Justice Ron George estimates on Wednesday three million cases statewide will be delayed, 150 jury trials interrupted and 250 child custody cases will not be heard.
Attorney James Lewis says he may reassess the cases he decides to handle.
"Do you take a case to trial knowing it'll take you two weeks to try what would normally be a one week case," he said.
The once-a-month furlough means court workers will not get paid. Deputy court clerk Rochelle Veluz says she'll have to cut back.
"Some expenses, like with the kids, just preparing them lunches every day instead of buying lunch at school," said Veluz.
The courts will still provide emergency services including search warrants for police and restraining orders for victims of violence.