Know It All: Vernal Equinox

A derivative of Latin, the word equinox literally means equal night. Twice a year—March 20 or 21 and September 22 or 23—the sun crosses directly over the equator. At the moment of the March and September equinoxes, the length of day and night are nearly equal around the globe. While we welcome the spring in the northern hemisphere, the March equinox signifies the beginning of fall in the southern hemisphere. The seasons will flip on the September equinox when the northern hemisphere turns to fall and the southern hemisphere blooms in spring.

The fall and spring equinoxes are also the only two times a year when the sun rises due east and sets due west. In North America there are numerous large stone structures, including America's Stonehenge in Salem, NH, which point directly to the sunrise and sunset on the equinoxes. The ancient Egyptians built the Great Sphinx to directly face the rising sun on the vernal equinox.

Since ancient times, the Mayan city Chichen Itza has served as the celebratory site for The Return of the Sun Serpent on the spring equinox. During the late afternoon, the setting sun casts triangular shadows down one of the railings of the great ceremonial pyramid, El Castillo, simulating a descending snake that’s said to be the feather serpent god Kukulkan.

As the birds and bees get back to business, spring fever is in the air and common symbols of fertility—such as eggs and the hare—appear cross-culturally in March festivals. (According to Chinese legend, you can balance a raw egg on its end on the day of the spring equinox.) Some continue to celebrate the Germanic spring festival Ostara in honor of the Saxon fertility goddess Eostre—who gave her name to the female hormone estrogen and the festival of Easter—on the full moon following the spring equinox. (Easter is always the first Sunday following that full moon.)

At the vernal and autumnal equinoxes, the Japanese national holiday Higan is observed for one week (three days before and after the equinox). Higan means the other shore and refers to the Buddhist concept of nirvana: the passage of dead spirits from the world of suffering to the shores of enlightenment. It is a time to pay respect to ancestors: Gravesites are visited, tombs are swept clean and offerings of flowers and incense are made.

According to the astronomical Persian calendar, the Iranian New Year (known as Nowruz or No Ruz) starts on the vernal equinox. Widely cherished and celebrated throughout Iran, Nowruz—meaning new day— is a celebration of rebirth and renewal, and is typically kicked off with the annual cleansing of the home. While the origin of spring cleaning is still up for debate, long standing traditions of nearly all cultures involve dusting off and sprucing up around the vernal equinox. So clear out those cobwebs, let the fresh sunshine in and get to it!