Our body got a natural time table. Like for example it is said that morning and before evening is the best time to exercise. Well....you can go gym and work your body at midnight.....just that your body is at resting period that time

The best time to get the best quality sleep is from 11pm to 2am. That is the time when the body is supposed to be resting.

Those who work night shift but still able to sleep at 8 hours, look normal?...that is possible....but ask them, do they feel heaty? compared to when they work at day and sleep at night

To learn more, check this out: Circadian rhythm