Fall Equinox

Today is the fall equinox. The length of the day is equal to the length of the night. Actually the path of the sun in the sky, from its rise in the morning to setting in the evening is exactly half way between its highest path in the summer and its lowest path in the winter. Roughly the highest path is on June 21st (summer solstice), and the lowest path is on December 21st (winter solstice). The equinox happens twice on September 21st and March 21st.

Our calendar is connected with the winter solstice, and the Jewish calendar is connected with the fall equinox. The Persian calendar is connected with the spring equinox. I am not aware of any modern calendar that begins with summer solstice.

Exact time is maintained by the atomic clocks such as those at the National Institute of Standards and Technology (NIST). These time signals provide accurate time and synchronization for all kind of applications in civilian, business and industrial and military applications. Click to see the official US time clocks for different regions of the country. The official U.S. time