Spring begins with the vernal equinox on March 20 at exactly 1:32 P.M. EDT.
The word equinox is derived from the Latin for “equal night” and is used now because the days and nights are of nearly equal length.
The vernal equinox is the point at which the center of the Sun passes over the celestial equator from south to north, signaling the start of nature's renewal in our hemisphere.
After the equinox, the Sun will appear higher and higher in the sky, and length of day will grow longer than the length of night.
Notice that March 20 does not have exactly the same number of hours for day and night. By the time the center of the Sun passes over the celestial equator, the day will be slightly longer than the night. Why?
• Light rays from the Sun are bent by Earth’s atmosphere. We actually we see the Sun before it rises and after it sets.
• Daytime begins the moment any part of the Sun is over the horizon, and it is not over until the last part of the Sun has set. If the Sun were to shrink to a star-like point and we lived in a world without air, the spring and fall equinoxes would truly have "equal nights."
It is said that one can balance an egg on it's end at the equinox.
However, one can stand an egg on it's end on any day if they have the patience.