My niece and nephew have perfectly regular sleep schedules. As in their sleep schedules are super consistent.

Is it "regular" like "regular people have it"? Fuck no!

But their schedule is like clockwork with it's regularity.

Wake up at 4am, full of energy until 4pm, unconscious until 8pm, wide awake until midnight, asleep until 4am, repeat. They're 10 now and I really hope they get a job someday that let's them keep that kind of schedule because it works so well for them.

EDIT: I should clarify though that their schedule is almost perfectly at odds with my brother's (their dad) schedule.