Legal Question in Business Law in California

I THINK the correct answer is that no notice is required under the law; this guess is based on the fact that no prior notice is required to fire an employee...UNLESS there is a contract provision (in a union contract or a personal employment agreement) to the contrary. I am on the road at the time of answering your question and don't have my reference library handy.

Mr. Whipple is correct. Unfortunately California is a very employee un-friendly state on this issue. If you show up and they send you home, they must pay you the difference between any time worked and 1/2 your regular shift, up to 4 hours total, but if they call you before you get there, you are not entitled to any compensation.