The equinox is one of the two times in a year when the sun crosses the plane of the earth's equator, and day and night are of equal length. “During the spring equinox you can balance eggs on end, because of the equal balance between night and day.”
There are two equinoxes every year, one in the spring (the vernal equinox) and one in the fall (the autumnal equinox), each usually on the first day of spring and the first day of fall. These days are often celebrated and even worshipped in some traditions, although an equinox is actually a point in time — not an entire day.
