Vernal Equinox

Today is the first day of spring. The vernal equinox occurs today, the time when the Earth’s axis is not turned toward the sun (summer, for those of us in the Northern Hemisphere), or away from it (winter), but is aligned with the center of the sun. The word equinox comes from Latin: aequus means equal, level, or calm; nox means night, or darkness. The equinox, in spring or fall, is a time when the day and night are as close to equal as they ever are, and when the hours of night are exactly equal for people living equidistant from the equator either north or south.
- Writers Almanac