With respect to California's stated rates of time and a half for work performed beyond 8 hours and double time beyond 12 hours, are these minimum rates or are they specifically mandated? In other words, is an employer free to establish a rate of, say, time and three quarters for work performed beyond 8 hours but less than 12? Thanks.

They are specifically mandated; however, neither the state nor the Federal government is ever going to tell an employer they cannot do more for the employees than the law requires. They cannot do less than the mandate, but they can do more than the mandate.

Thanks for the response - much appreciated. I agree with your assessment, but I always worry that California will view any deviation from mandated law as a disguised subterfuge. That's the kind of paranoia that results from practicing in California for too long.