4 ms·

The constant "time zone" changes might throw a wrench into calculating the offsets. How far in advance can we calculate sunrise/sunset times?

mschuster91 5y ago
Infinite, there is a mathematical formula: https://en.wikipedia.org/wiki/Sunrise_equation https://en.wikipedia.org/wiki/Sunrise_equation
Arubis 5y ago
Depends on what you mean by sunrise/sunset. “The relative position of the sun’s edge drops below/rises above the tangent of the average surface at sea level” is pretty easy to calculate many years out; the complications are deviations in Earth’s orbit. “I can/can’t see the sun anymore” depends on local weather, good luck.
- registeredcorn 5y ago
  > “I can/can’t see the sun anymore” depends on local weather For anyone wanting to know a bit more about why this is, here's some additional details: https://www.youtube.com/watch?v=-sj868IzNrk https://www.youtube.com/watch?v=-sj868IzNrk https://en.wikipedia.org/wiki/Atmospheric_refraction https://en.wikipedia.org/wiki/Atmospheric_refraction Technically, one might also argue something weird like, "If I can see sunlight, it's still daytime" in which case a different phenomina would come into play: https://www.atoptics.co.uk/highsky/zod1.htm https://www.atoptics.co.uk/highsky/zod1.htm https://en.wikipedia.org/wiki/Zodiacal_light https://en.wikipedia.org/wiki/Zodiacal_light What this all comes down to is, roughly speaking, even after the sun has technically set, there's still a bit of leeway before we no longer see the sun/sunlight due additional factors.
at_a_remove 5y ago
I am frustrated in the faintness of memory, but I dimly recollect an area which, for about two years, altered time every day so that noon was when the sun was directly over head. Something Royal Time, or something Solar Time. There are some weird time zones out there.

mschuster91 5y ago

Infinite, there is a mathematical formula: https://en.wikipedia.org/wiki/Sunrise_equation https://en.wikipedia.org/wiki/Sunrise_equation

Arubis 5y ago

Depends on what you mean by sunrise/sunset. “The relative position of the sun’s edge drops below/rises above the tangent of the average surface at sea level” is pretty easy to calculate many years out; the complications are deviations in Earth’s orbit. “I can/can’t see the sun anymore” depends on local weather, good luck.

registeredcorn 5y ago
> “I can/can’t see the sun anymore” depends on local weather For anyone wanting to know a bit more about why this is, here's some additional details: https://www.youtube.com/watch?v=-sj868IzNrk https://www.youtube.com/watch?v=-sj868IzNrk https://en.wikipedia.org/wiki/Atmospheric_refraction https://en.wikipedia.org/wiki/Atmospheric_refraction Technically, one might also argue something weird like, "If I can see sunlight, it's still daytime" in which case a different phenomina would come into play: https://www.atoptics.co.uk/highsky/zod1.htm https://www.atoptics.co.uk/highsky/zod1.htm https://en.wikipedia.org/wiki/Zodiacal_light https://en.wikipedia.org/wiki/Zodiacal_light What this all comes down to is, roughly speaking, even after the sun has technically set, there's still a bit of leeway before we no longer see the sun/sunlight due additional factors.

at_a_remove 5y ago

I am frustrated in the faintness of memory, but I dimly recollect an area which, for about two years, altered time every day so that noon was when the sun was directly over head. Something Royal Time, or something Solar Time. There are some weird time zones out there.