This is gonna sound completely ignorant but I don't remember seeing a major crew doing nights on DS9. Somebody help me out here.
It was always night on DS9.
Well, a routine watch on a (relatively) stationary space station is going to be a lot smaller than a starship, IMO. Maybe only the equivalent of an engineering/security type wandering the areas once/hour, perhaps a second individual manning the Command deck (or whatever it was called in DS9 -- can't recall off-hand), and then the OOD.
The latter is probably really only "on call", so after 2300 or thereabouts (i.e. after one last round of the spaces), they're probably in the rack.
Cheers,
-CM-