Talk:Length of day

Proposed material

 * Length of day is calculated by
 * $$\cos H_0=\frac{\sin(-0.8333^\circ)-\sin \delta \sin \varphi}{\cos \delta \cos \varphi}$$
 * $$\delta$$ is the Sun's declination
 * $$\varphi$$ is the geographical latitude


 * $$H_0$$ is an angle between 0&deg; and 180&deg;


 * If $$\cos H_0$$ is less than &minus;1 then the Sun is circumpolar.
 * If $$\cos H_0$$ is greater than +1 then the Sun is down all day.


 * Divide $$H_0$$ by 360&deg;. Then multiply by 24 hours. Then multiply by two. This last result is the length of day (hours).
 * Sources

Iceblock (talk) 04:42, 29 January 2015 (UTC)