i’m just working on some flags which should give me the option to reacht on various “time”. example: Night ist between atroDawn und astroDust of the Astro binding. So far so easy, but in the astro binding i found two type where i am not able to translate them to german or understand them in english, because i find no explanation. Maybe someone could help me out.
Firt thing i reconized is that sunrise and sunset have a duaration of 4 minutes. Next is that the night stops two minutes after AstroDown and that there is a difference of about one hourbetween Moning Night Stop and Astro Dawn Start /Night Stop.
Could someone give a statement on this? Bob remarked the asymmetry as well.
As sunrise and sunset are calculated from the leading and trailing edges of the Sun, respectively, and not the center, the duration of a day time is slightly longer than night time (by about 10 minutes, as seen from temperate latitudes). Further, because the light from the Sun is refracted as it passes through the Earth’s atmosphere, the Sun is still visible after it is geometrically below the horizon.
So I guess the four minutes for the sunset and sunrise events might match the transit of the sun disk across the horizon line?