Due to the eliptical nature of Earth's orbit about the Sun, though we haven't reached Winter Solstice yet, we have already seen the earliest Sundown. At 40 degrees N. Lat. it was 1635 hrs. from about the 1st through the 14th (perihelion reached on or about the 10th, I believe, Earth's closest approach to the Sun). If you were to mount a camera on a fixed location and (with proper filters) snap a picture of the sun at the exact same time every day and then overlay the pictures you would see something that looks like a long strectched out "figure 8". They used to print this on globes and the technical name for it is "analema". I just now checked a little desk dictionary and the word is not in there. I know I have left out a few important details and interesting other points like the location of the tropics and precession of the axes, but hey Mudcatters! Have at it. Tell us what you know!