From the house rabbit society:
Rabbits are actually “crepuscular”, meaning they are most active in the twilight hours of both sunrise and sunset.
This is because before becoming domesticated, rabbits evolved as a prey species for thousands of years. Evolutionarily it was safest for rabbits to leave the safety of their burrow and forrage for food in the transition between day and night when the light is dim. This is the time when nocturnal (night) predators such as owls can’t see well because of too much light, and when diurnal (day) predators such as foxes, can’t see well because it is too dark. Smart bunnies!
Now from me – rabbits will begin to take on your sleep schedule as instead of foraging for food safely, they will ‘forage’ for the food when you give it to them. So they have no further ‘prey/predator’ safety issues. It make take a few months but mine (mostly) sleep when I sleep.