sunrise-sunset function from
solar.el computes sunrise and sunset. I would also like to have a function that computes the end/beginning of
- civil twilight (center of sun 6 deg below horizon)
- nautical twilight (center of sun 12 deg below horizon)
- astronomical twilight (center of sun 18 deg below horizon)
Does anyone know of elisp-code (or a package) for computing said times?
Edit: There seem to be a solution within
solar.el: The function
solar-sunrise-sunset calls the function
solar-sunrise-and-sunset with a HEIGHT of -0.61 degrees (half the apparent diameter of the sun). Using a HEIGHT of -6 degrees should give the end/beginning of civil twilight, and similar for the other.