An explanation of celestial mechanics in the popular press: "The earliest sunset really comes in the first week in December, and the latest sunrise occurs in early January. Yet December 21 really is the shortest day of the year. What sort of astronomical hijinks are responsible for this absurd state of affairs?"
http://www.theatlantic.com/technology/archive/2013/12/the-astronomical-hijinks-of-the-shortest-day-of-the-year/282109/ --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
