We're pretty relaxed about sleep here really. I have to take medication every 6 hours for the rest of my life, so I don't get to bed until midnight or so, and wake between 6 and 8am. DD has ASD and is a night owl, and often goes to sleep 2-5am and sleeps until noon-1pm. If she's not up by 1pm I generally start trying to wake her so we can do school while the sun is still up, as our school area doesn't have good artificial light.
I really really wish she slept on a normal schedule sometimes - trying to get her up for field trips early is terrible!