Legal Question in Employment Law in California

Unless you have a union or personal contract, or civil service rule, to the contrary, yes.

Yes. In general, unless an employee is civil service, in a union, or has a written employment contract, they are an 'at will' employee that can be disciplined or fired any time for any reason, with or without �cause�, explanation or notice, other than for illegal discrimination, harassment or retaliation under the ADA disability, Civil Rights [age, race, sex, ethnic, religion, pregnancy, etc], Whistle-blower, or similar statutes. The employee's goal should be to keep the employer happy.