Sun Shadow

This is an app which draws the shadows of buildings on a map.
For a designated day, it calculates the hour angle, the equation of time, the time of sunrise, the time of sunset, the culmination time, and length of day.
For a designated time, or for hourly intervals, the app calculates the length of shadows, and the direction and elevation of the sun.
The options for the units of length are: feet or meters.

Calculations are done on the following basis:
* The ground on which the shadows are drawn is assumed to be flat.
* The declination of the sun is calculated using an approximation formula.
* The latitude is limited from -85 to 85°.