Saturday is spring

Far from being an arbitrary indicator of the changing seasons, March 20 (March 21 in some years) is significant for astronomical reasons. On March 20, at precisely 1:32 p.m. EDT, the Sun will cross directly over the Earth’s equator. This moment is known as the vernal equinox in the Northern Hemisphere. For the Southern Hemisphere, this is the autumnal equinox. Modern astronomy aside, people have recognized the vernal equinox for thousands of years. Many early peoples celebrated for the basic reason that their food supplies would soon be restored. It is probably no coincidence that early Egyptians built the Great Sphinx so that it points directly toward the rising Sun on the day of the vernal equinox. The date is significant in Christianity because Easter always falls on the first Sunday after the first full moon after the vernal equinox. From: infoplease.com