The beginning of spring and the beginning of fall are the only two days
of the year at which the northern half and the southern half of the Earth
are bathed in equal amounts of sunlight. The word equinox means 'equal
night'.
As the Earth moves around the Sun (revolves), the angle of sunlight
on the surface of the Earth changes from season to season. The Sun will
rise due east and set due west on the vernal equinox and appear to get
higher and higher in the sky each day slowly warming the air and melting
the snow.
Spring officially begins at 2:35am. on March 20th, 2000.
