Legal Question in Employment Law in California

Generally, schedule adjustments are within the discretion of the employer, but additional facts could indicate the adjustments are illegal in your case if retaliatory. For example, let's suppose the employer was not delivering your earned tips, and you protested that the tips belonged to you. If your employer then cut your hours, or put you on a "slow" shift, you could have a "wrongful adverse action in violation of public policy". The "policy" would be a legal one requiring employers to timely deliver agreed earned wages to their employees.