The Photographer's Ephemeris (TPE) application provides detailed information with the exact position of the sun and moon as viewed from a particular location on a on a given date and time. TPE also provides shadow length, and whether or not a subject will be in shade at a given time. Click on the next icon to open The Photographer's Ephemeris centered on
TPE is published by Crookneck Consulting LLC and the web application is free to use.
There are many apps available for your phone or tablet to help with shot planning. My favorites are Photopills and TPE for Android/iOS or TPE 3D for iOS only. Both applications support the importing of Points of Interest / Locations. To import POIs for Lake Powell into one of these apps proceed as follows:
The Sunrise Sunset calculator above provides a monthly calendar showing Sunrise/Sunset and Moonrise/Moonset and Moon phase for a whole month. More detailed information can be obtained by clicking on one of the Photographer's Ephemeris icons above or via one of the mobile applications listed.
Sunrise Sunset times are given at Rainbow Bridge which is in Utah so DST is in effect part of the year.