Can you legally be scheduled over your FTE?

[SuperburntoutRN]

Hi. I've been a nurse over ten years and have always worked a 0.9 FTE or three twelve-hour shifts per week to equal 36. Recently I moved to a unit where we do 4 shifts a week 0.9 FTE. 0700-1730. That is 40 hours a week yet we are only required to work 36. We are outpatient and are not always there until 1730 but sometimes we stay past that. If we ask for vacation, we are only allowed to 72 hours even though we are scheduled 80. I know hospitals do this all the time but can they LEGALLY actually do that and not make us a 1.0 FTE? I have never seen other floors schedule 3 twelve hour shifts and then make them come in 4 extra hours every week. Are there any department of labor laws to look into? Thanks.