The first day of spring, also known as the vernal equinox, marks the first of two days during the calendar year when the sun shines equally on both the northern and southern hemispheres. Occurring March 20-21, the vernal equinox has symbolized the renewing of the earth and inspired traditional celebrations since the birth of human civilization.
Historians credit Greek astronomer Hipparchus, in 120 B.C., with observing the two times when the sun shines directly on the equator. However, solar and lunar cults that predate pagan religions are thought to have celebrated the end of winter as long as 8,000 years ago.
Among the earliest recorded spring holidays, the Pagan and Celtic celebration of the goddess Eostre heralds the return of warmth and fertility. Historians believe early Christians incorporated Eostre into their Easter resurrection celebration. The week-long Buddhist higan, a Japanese national holiday since the dawn of the 10th century, also occurs during the time of the vernal equinox.
The ancient Mesopotamian celebration Akitu marked the spring cutting of the barley crop. In the Mideast, the vernal equinox marks the first day of the new year in the Afghan Nowruz calendar.
In the United States, the first day of spring has become the highly anticipated date of such varied celebrations as gardening fairs, arts festivals and kite-flying contests.
For the early Celtic Druids, the vernal equinox came in midseason. Imbolc, their traditional first day of spring, fell in early February, on or around what is now known as Groundhog Day.