sun time matches clock time in Herndon

Having taken a very strong interest in time zones and clocks the last few months due to Indiana's changing time situation, I found it an interesting coincidence to discover that I had arrived at my hotel in Herndon, Virginia yesterday (December 5) on one of the only two days of the year when the sun happens to pass directly overhead here at noon (the other is September 28).

At 77.4 degrees longitude, Herndon is 2.4 degrees west of the middle of the eastern time zone (75 degrees). Thus, its local mean time is about ten minutes behind clock time. However, the correction due to the equation of time exactly cancels out the longitude correction on these two days.

The irony was not lost on me that the closest the clocks in Indianapolis will come to ever reading 12:00 when the sun is overhead if we are on eastern time is 12:28pm on November 23. Worst case falls on July 26, when our clocks will read 1:51pm as the sun passes overhead in 2006.

If we were on central time, the clocks would read approximately 12:00 noon with the sun overhead in Indianapolis on February 11.