The Science and Traditions of Spring Equinox Celebrations.

The vernal equinox, which marks the beginning of astronomical spring, occurs on March 20 at 5:24 p.m. Earth's tilt causes the sun's rays to shine directly over the equator, resulting in equal amounts of daylight and night, except for a few extra minutes of daylight due to the sun's refraction and sunset definition. Contrary to popular belief, the equinox has nothing to do with balancing eggs. On the equinox, the sun sets faster than on the solstices due to simple geometry.