Time Served Credits in California. Before January 25, 2012, a defendant received 50% credits meaning 2 days for every 4 served. Effective January 25, 2010, a defendant gets 100% credits, meaning 4 days for every 4 days served unless the defendant had a prior strike, the current conviction was for a strike or the defendant had to register under Penal Code section 290. Effective September 28, 2012, defendants received 50% credits, meaning 2 days for every 4 days served if the defendant served time in county jail. If the defendant was sent to state prison, then the defendant got 100% credit. Effective October 1, 2011, defendant gets 100% credits, meaning 4 days for every 4 days excluding violent felonies and murder.