(13) Solar and clock noonJan 7, 2013

In our time, noon is defined as 12 o'clock in the daytime, but from ancient time to modern time, noon was defined as the time when the Sun was due south. However, apparent solar noon is either ahead of or behind clock noon depending upon the season of the year. The latest solar noon is at 12:14:13 Japan standard time on February 11, while the earliest solar noon is at 11:43:35 on November 3. The equation of time is about 30 minutes in a year. This is due to the Earth's axis inclination and elliptical orbit. Because of this, the earliest sunset does not occur on the winter solstice, but rather about two weeks earlier around December 5. The day and night are equally long on the spring and fall equinox, but the most different equation of time are likely to occur on February 11 and November 3. Is it just coincidence that the largest equation of time occurs on Japanese national holidays, National Foundation Day and Culture Day?
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