<P> An equinox is commonly regarded as the moment the plane of Earth 's equator passes through the center of the Sun 's disk , which occurs twice each year , around 20 March and 22 - 23 September . In other words , it is the point in which the center of the visible sun is directly over the equator . This simplified , but incorrect , understanding of Earth 's orbital motion can lead to errors of up to 69 seconds from the actual time of equinox . </P>
<P> An equinox is commonly regarded as the moment the plane of Earth 's equator passes through the center of the Sun 's disk , which occurs twice each year , around 20 March and 22 - 23 September . In other words , it is the point in which the center of the visible sun is directly over the equator . This simplified , but incorrect , understanding of Earth 's orbital motion can lead to errors of up to 69 seconds from the actual time of equinox . </P>
during which two months ( equinoxes ) do all locations on earth experience 12 hours of daylight
during which two months ( equinoxes ) do all locations on earth experience 12 hours of daylight
March September
March September