Sleeping meets the needs of rest of each individual, although the sleep time should not be less than five to six hours ,are ideally eight, always referring to the nighttime hours for at that moment is when it causes the release of melatonin (a hormone that induces sleep) that is inhibited by light and stimulated by darkness. Melatonin may help to keep our bodies in order to know when it's time to sleep and when to get up.