March Equinox is the time when the sun shines on the Equator, directly overhead. This is the day of equal Day and equal night that is 12 hours of day and night at Equator locations. In Northern locations the March equinox signifies the beginning of spring season and also known as Vernal Equinox. However, in Southern locations the March equinox signifies the beginning of autumn season and is also known as Autumnal Equinox.