Here is a clear and concise explanation of the vernal equinox, the first day of spring, which falls on March 20 at 5:15 GMT, but on March 19 in most of the United States, depending on your time zone. You will find a diagram of the earth and its positions at the solstices and equinoxes throughout the year as well as a table showing the time of the vernal equinoxes through 2020. There are also links to definitions of many of the specialized vocabulary words used in describing this yearly occurrence.
courtesy of netTrekker
