7 off in 28 is the legal minimum with an average of 24 in 84 days.
Depending on the fleet.
B777 is duty day limited, AB MFF pilots very high on hours with a small number clost to max 900 blk 12 month period. Some have exceeded and have been removed from flying the following month.
Full Preferential rostering system, with company constraints, on a rotating seniority. Pilots who know how to use the system usually get what they bid for irrespective of were they are on the seniority list for that month.
Expectations can be high, but as I say, basically, the clever ones get what they want.
Days off per month can range from 8 to as high as 16 with spreads of 6-8 consecutive days off, and even more when days off are back to back from one month to the next.