Once in a while a tool comes along that you wonder how you ever lived without. The Photographers's Ephemeris is one of those tools for me. First released in 2009, I just found it accidentally in April this year. Since then it is the first thing I use when planning a sunset photo shoot. (Confession: I had to look up the word Ephemeris. It is a table or data file giving the calculated positions of a celestial object at regular intervals throughout a period of time).
The Photographers' Ephemeris, (TPE), is an app that shows you the position of the sun and the moon on any day, anywhere in the world. Based on Google Maps platform, one can search for a location and a pin is placed on the map there. If available for the spot you can even go into Google Street view. The sun/moon movement is tracked over time. TPE is a free desktop application. It has a paid app for the smartphone as well.
Using the tools in TPE you can even calculate where the shadows of nearby elevations will affect your view. TPE has recently come out with a new app for smart phones. TPE 3D, which shows the shadows falling over the earth in 3D.