92 Guaranteed days off per year and 42 days vacation leave per year. The vacation leave will be in 7 day blocks, but sequential blocks can be bid for in the yearly allocation or potentially shifted around later in a pool.
900 hours max flight time per year with breaks around FTL limitations.
Stack continuously shifting rosters and time on a string around that and that is your life.
There is no bidding, and there is no form of predictability between the published and actually executed roster. Published rosters are largely placeholders for a continuous 'vul' window between GDOs.
What Natca said is largely the way it is.