Legal Question in Employment Law in California

Completely legal. If they fired you for not showing up with so little notice, you would probably still be entitled to unemployment, but there is nothing illegal about it. You are an at-will employee. That means you have no rights to any particular job, tasks, hours or anything else, as long as they pay you the rate they tell you they are going to pay you, at minimum wage or higher, and with the rest and meal breaks required by law. You are there to do what the employer decides you are going to do as long as it is not illegal. If you want rules about what work you do and what work you don't do, join a union, see if your union can unionize the place you work and THEN see if they can negotiate a work rules contract. Otherwise, go to work when you are told, do what you are told as long as it is not illegal, and collect your pay -- or find another job. Those are the only options the law gives you.