Sunrise Equation

The sunrise equation, also called the sunset equation, is a formula that calculates when the sun rises or sets at a given location on Earth. It works from two astronomical quantities, the sun's declination and the observer's latitude, converting between the equatorial and horizontal coordinate systems to find the moment a celestial object crosses the horizon. In its basic geometric form the equation ignores atmospheric effects, but more refined versions account for atmospheric refraction and the sun's apparent size, giving the greater accuracy needed for practical uses such as astronomical almanacs. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/