Circadian clock precision, chronotype, health and longevity

Accurate circadian clock, predetermined by precise intrinsic period, tau may be linked with definite chronotype and health status. Exemplified by different animal species, and, as we argue herein, may as well be in humans, endogenous tau close enough to 24 hours is associated with higher life expectancy, lower morbidity and is possibly adhered to moderate morning chronotype. Accurate circadian tau facilitates maintaining high amplitude of circadian rhythms, a phenotypic trait that is related to health and longevity. Some genetic factors that coordinate tau and ensure circadian clock precision are considered.