Circadian rhythm

Patent Granted A circadian rhythm /sɜrˈkeɪdiən/ is any biological process that displays an endogenous, entrainable oscillation of about 24 hours. These rhythms are driven by a circadian clock, and rhythms have been widely observed in plants, animals, fungi, and cyanobacteria. The term circadian comes from the Latin circa, meaning "around" (or "approximately"), and diem or dies, meaning "day". The formal study of biological temporal rhythms, such as daily, tidal, weekly, seasonal, and annual rhythms, is called chronobiology.