When can I get my driver's license in California?

I got my learners permit on March 10, 2011 and I just started driver's training today. The lady who gave me my permit said I could test for my license on September 12, 2011. But my instructor said to wait 6 months? So I am confused as to when I should schedule an appointment with the DMV to test for my license. Can anyone verify things for me?