Modules
Agricultural sun & moon calendar — pure Elixir, zero dependencies.
Low-level facade: apparent positions, phase, rises and sets.
Position of the Moon: truncated ELP-2000/82 theory as published by Meeus, Astronomical Algorithms (2nd ed.), chapter 47.
Generic search for rises, sets and meridian transits.
Position of the Sun, Meeus' "low accuracy" method, chapter 25.
Time scales, Julian day, ΔT, sidereal time, nutation and obliquity.
One computed civil day — the return type of GreenCal.day/3.
Lunar part of a GreenCal.Day.
Solar part of a GreenCal.Day.
Twilight part of a GreenCal.Day.