ART is not quackery (nor is chiropractic, but unfortunately that stigma has prevailed...). To become a certified ART practitioner, one has to spend a lotta time and money. In other words, the certification criteria appear to be pretty stringent. You may want to confirm your chiro is certified by the ART folks.
The Equinox (Vernal & Autumnal) There are only two times of the year when the Earth's axis is tilted neither toward nor away from the sun, resulting in a nearly equal amount of daylight and darkness at all latitudes. These events are referred to as Equinoxes.The word equinox is derived from two Latin words - aequus (equal) and nox (night). At the equator, the sun is directly overhead at noon on these two equinoxes.
In the Northern Hemisphere the vernal (or spring) equinox (equi, âequal,â and nox, ânightâ) occurs between March 19 and 23, but usually on March 21. During both equinoxes, all locations on Earth experience 12 hours of daylight and 12 hours of darkness, and the Sun rises due East and sets due West.