Equinoxes and the circadian rhythm

The spring and autumn equinoxes lie halfway between the shortest and longest days of the year. At these points, day and night are mostly even lengths all over the world.

These conditions may suit the human circadian rhythm - the daily cycle that affects the body's sleep, wake, eat, and other biological processes. The benefits of a well-entrained body clock include modifying your metabolism, decreasing cardiovascular disease and better eyesight.