The human body naturally tends to follow a cycle of sleeping and waking that corresponds to a:

The appropriate response is the circadian musicality of a 24-hour cycle. A circadian musicality is an approximately 24 hour cycle in the physiological procedures of living creatures, including plants, creatures, organisms and cyanobacteria. In a strict sense, circadian rhythms are endogenously produced, despite the fact that they can be balanced by outside prompts, for example, daylight and temperature.