Legal Question in Employment Law in California

Unless you had a contract for a specified time, you are an at-will employee. That means they can fire you at any time for any reason or no reason at all, as long as it is not in violation of discrimination laws, and you can quit any time. The at-will status, by implication, has wrapped up in it the right to change the terms and conditions of your employment at any time, subject to your right to quit and their right to fire you. So you are free to unilaterally change to a 3-day work week. They can accept it or fire you. They can demote you, reduce your pay, change your vacation policy, increase your work load, etc. You can accept it or quit. The only two things they cannot do are 1) apply any changes in a discriminatory manner based on age, gender, race, or any other legally protected classification you may fit in, and/or 2) reduce pay or benefits for time already worked by you prior to notice of the change.