Hi Joe,
We spend 24 hours at most layover destinatons. The majority of pairings return to Dubai the following day, but some (mostly 777) trips go further afield (notably Oz/NZ) and can be gone for max 11 days! On the other hand, some trips we get min rest at the hotel!!
Depends what suits the company best commercially. Fatigue and our wishes have no bearing on rest.
Regards, CC.