Is there anything special about sleeping at night as opposed to sleeping during the day?
Short answer – yes.
Sleep quality is dictated by your body clock. Sleeping at night means, for most people, that you are following your circadian rhythm, which boosts your sleep quality tremendously. When the sun goes down, your body will prepare for going to sleep. In most people, the sleep chemical, melatonin, is produced and released from the pineal gland in the evening. Disrupting your natural rhythm can have an impact on your health and well-being, as anyone who has to work night shifts will tell you.
Even though we have evolved to recharge during the night, most people feel an energy slump during the day, especially after heavy lunch. The temptation is often to take a nap. For some people, the nap will have absolutely no negative effect on their sleep at night. For others, however, a nap taken during the day, may make it much harder to fall asleep the night. So try to avoid naps after 3pm.