I know my own sleep basically drifts later and later until I run into hard deadlines. I'd be surprised if most people don't work that way, in a vacuum.
[0] https://en.wikipedia.org/wiki/Delayed_sleep_phase_disorder
[1] https://en.m.wikipedia.org/wiki/Non-24-hour_sleep%E2%80%93wa...
I know my own sleep basically drifts later and later until I run into hard deadlines. I'd be surprised if most people don't work that way, in a vacuum.