The date of earliest sunset depends on Latitude and is not always Dec 14. See: http://www.idialstars.com/eass.htm
> Dear Colleagues > > In the depths of a freezing Northern winter, there's time to think about > days of special interest. There are six significant solar dates around > this time of the year. > > Three are special and probably known to all... > 21st December - half an hour before midnight - the Winter Soltice > 25th December - not only Christmas day, but one of the four days in the > year when the equation-of-time is zero. > 3rd January - Perihelion when the Earth is closest to the Sun, > > One day is perhaps of interest only to the serious heliochronometer > user... > 23rd December - the day when the equation of time is changing at its > maximum rate of almost 30 secs/day > > Two days are nothing more than obscure, except to the numerically obsessed > - or to those who like strange questions to ask on quiz nights.... > 14th December - the day on which the Sun sets earliest in the day > 29th December - the day on which the Sun rises latest in the day > See the graph below. If you wonder why this is so, it is because there are > two effects in play (a) the daily change in sunrise/sunset as a result of > declination change is minimal around the solstice and (b) the effect of > the equation of time with its large eccentricity component as the Sun > races forward towards perihelion. > > p.s. the graphs are for 54 degrees North latitude; the y-axis scale will > change at other latitudes. > p.p.s. dates are UT - so they may vary with your local longitude. > > Have a wonderful Christmas season. > > Kevin Karney > > --------------------------------------------------- > https://lists.uni-koeln.de/mailman/listinfo/sundial > > --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
