I was hired to work 11-11 as a RN. I am hourly. I rarely get these hours. I am asked to come in earlier. We have no patients I go home early. I was suppose to work 3 days a week. That is 36 hours a week. I usually only get 32. Can they do this?

You are considered an at will hourly employee, yes they can. You can also choose to not accept this treatment but it is legal. However, you might have a case if they provided you with a job description or other docs stating your hours.