Maybe most creatures on such planets would evolve towards unihemispheric sleep, as some Earth species did (eg. dolphins).
Unihemispheric slow-wave sleep (USWS) is sleep with one half of the brain while the other half remains alert.
Light/dark is only one factor in sleep, there are others.
It's also hard to know of the infinitely many evolutionary twists and turns lifeforms in the Universe may take, how many of those pathways involve something like sleep - especially on planets without a diurnal cycle.
Anything and everything is a wild guess based on a sample of one where extraterrestrial life is concerned.