Time, Calendars, and SeasonsThe Seasons |
What are the equinoxes |
There are two equinoxes—one on March 21 and the other on September 21. On both equinoxes, the sun is directly over the equator. March 21 heralds the beginning of spring in the Northern Hemisphere and the beginning of fall in the Southern Hemisphere. September 21 heralds the beginning of fall in the Northern Hemisphere and the beginning of spring in the Southern Hemisphere.