Re: Sunrise time glitch?
Now the Solar declination is more than halfway from its Yul (Winter-Solstice) value to its Ostara (Spring-Equinox) value. And, in mid-latitudes (mid-lat U.S., and similar latitudes in Europe), the daily insolation (ground-warming sunlight received by the ground) has likewise passed the halfway point between its Yul and Ostara values. And, tomorrow, the daily insolation at that latitude will be half of its annual maximum. That is, it will have a value that's half of its value at Litha (Summer-Solstice). Tonight, Leo is the early-evening-rising ecliptic-constellation. Its early-evening-rising now, just before the beginning of the Roman month of Martius, heralds the evening-rising of Virgo just before the beginning of the Roman month of Aprilis. Of course, during Aprilis, Virgo will be rising in the early evening sky On Tue, Feb 25, 2020 at 2:00 PM Dan-George Uza wrote: > Hello all, > > While doing some research for a paper, a friend of mine noticed peculiar > differences regarding sunrise times for his city (Alba Iulia, Romania). > They occur both on TimeAndDate.com as well as suncalc.org and -so far I > can tell- only in Romanian cities (Berlin and Vienna are okay). > > I figure sunrise times should be pretty much the same except for the leap > year cycle, but for example between December 1st 1930 and December 1st 1931 > the times differ by more than 15 minutes. What could be the cause? > > I also looked at Gian Casalegno's Sun Ephemeris and all the times check > out neatly there. > > -- > Dan-George Uza > --- > https://lists.uni-koeln.de/mailman/listinfo/sundial > > --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Sunrise time glitch?
Dan-- Evidently those two sources you named got their result from the same other source, which had made an error....or else one of those two sources got their result from the other. If the two years are separated by a leapyear (but 1930 and 1931 aren't), then there could be a 3-day difference in the correspondence between date and ecliptic-longitude. But, since there was no leapyear between those two dates, there was just the 1/4 day displacement that occurs at the end of a common-year. That wouldn't be nearly enough to cause that difference in sunrise or sunset times. ...or a sufficient difference in the EqT. So, evidently someone's error got copied and thereby propagated. 10 Tu Pisces 7th Februarius 25th On Tue, Feb 25, 2020 at 2:00 PM Dan-George Uza wrote: > Hello all, > > While doing some research for a paper, a friend of mine noticed peculiar > differences regarding sunrise times for his city (Alba Iulia, Romania). > They occur both on TimeAndDate.com as well as suncalc.org and -so far I > can tell- only in Romanian cities (Berlin and Vienna are okay). > > I figure sunrise times should be pretty much the same except for the leap > year cycle, but for example between December 1st 1930 and December 1st 1931 > the times differ by more than 15 minutes. What could be the cause? > > I also looked at Gian Casalegno's Sun Ephemeris and all the times check > out neatly there. > > -- > Dan-George Uza > --- > https://lists.uni-koeln.de/mailman/listinfo/sundial > > --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Sunrise time glitch?
Hello all, While doing some research for a paper, a friend of mine noticed peculiar differences regarding sunrise times for his city (Alba Iulia, Romania). They occur both on TimeAndDate.com as well as suncalc.org and -so far I can tell- only in Romanian cities (Berlin and Vienna are okay). I figure sunrise times should be pretty much the same except for the leap year cycle, but for example between December 1st 1930 and December 1st 1931 the times differ by more than 15 minutes. What could be the cause? I also looked at Gian Casalegno's Sun Ephemeris and all the times check out neatly there. -- Dan-George Uza --- https://lists.uni-koeln.de/mailman/listinfo/sundial
