Originally Posted By: Hikin_Jim
The dates vary year to year, and the solar event actually happens at a precise time.


The precise time is when the center of the Sun is on the same plane as the Earth's equator.

The max change in declination for the sun is above 24 minutes of latitude, or 24 miles north or south, from day to day. One some days, there is no change. The lareger changes are near the equinox, and the smaller ones near the solstices.