Adventist Youth Honors Answer Book/Stars/Equinox
The ecliptic is the path followed by the sun across the celestial sphere during the year. It crosses the celestial equator twice during the year, once at the Autumnal equinox and once at the Vernal equinox. The Vernal Equinox occurs on either March 20 or March 21. The Autumnal Equinox occurs on either September 22 or 23.