Here's a fun little utility to keep in your system tray showing the current phase of the moon and sunrise/sunset times. Lets you choose your location and any date to check what the moon will be doing and when the sun will rise and set.
We have a plethora of open-source C# software modules to help you with GIS, KML, shapefiles, shapefile output, dbf files and assorted database interfacing classes. Just click here to peruse or email us and ask.