rolling 8

Usually it means that you are not assigned to just one shift. You may work the first of the week on days, then two shifts on pms, and the following two on nights. Or a variation of this. It has nothing to do with overtime.

Rolling 8 has nothing to do with having time off between shifts, at least in the US.

Usually depends on the contract how many shifts you can work without a day off. I remember one contract that had people work 7 shifts before a day off (and we were bagged by day 7).

We also had to have 15 hours between shifts or overtime kicked in.

I've never heard the term before.

Ask your shop steward.

I say ask the Union - they know everything!