SunCalc is a nifty site and app by Torsten Hoffman that allows visitors to enter any location and date and find out all the details of that day's local solar path:
Dawn, sunrise, sun peak level, sunset, dusk, duration, altitude, azimuth, shadow length. It can even show you what the last Manhattanhenge looked like on July 13.
Bonus video: Neil deGrasse Tyson On Manhattanhenge
Bonus photo: Manhattanhenge by Dan Nguyen)