A couple of facts that we are probably all familiar with but just in case;
In FR;
1. DH on days off shouldn't happen
2. Days off are days off!
3. 5/4 is inifinitum except 6/3 twice a year.
4. Pilots will be pilots..........
5. Rostering depts will be rostering depts and chance their arm.......
When I come across a pilot that's positioned on a day off or been rostered for something odd outside the norm 5/4, I ask did you complain/point it out and get it changed?
Pilots response;
1. Didn't want to rock the boat got my command coming up.
2. Didn't want to rock the boat hoping to my transfer to Malaga/Alicante/Tenerife etc
3. Didn't want to rock the boat at all.
4. Suited me - WHAT??
5. If I got it changed they might move my sim and I want it out of the way...
6. Im new so didn't want to rock the boat.
You get the idea. So we don't do ourselves any favours and rostering depts know how to play the game.
Personally anything odd or weird thats appeared on my roster has always been changed back to how it should be. But you have to ask!