Not sure why you’re downvoted, this is HUGE. Most humans have a circadian rhythm that tends toward slightly longer than 24 hours, and waking up at the same time every day can be very difficult for some percentage of us.
That's if they are in a cave experiment: without that the sunlight cycle regulates it back to 24hr. But not for everyone, and that's N24/non-24, not DPSD, delayed-phase sleep disorder.
