A circadian rhythm is a roughly 24 hour cycle in the physiological processes of living beings, including plants, animals, fungi and cyanobacteria.
In a strict sense, circadian rhythms are endogenously generated, although they can be modulated by external cues such as sunlight and temperature.
Circadian rhythms are important in determining the sleeping and feeding patterns of all animals, including human beings.
There are clear patterns of brain wave activity, hormone production, cell regeneration and other biological activities linked to this daily cycle.
Understanding your own circadian rhythm can help you focus on the most thought and/or physical intensive tasks during the times when maximum alertness and performance are peak.
Note: The above text is excerpted from the Wikipedia article “Circadian rhythm”,
which has been released under the GNU Free Documentation License.