Lew and everyone else, Sorry this thread seemed to drop off the face of the mailing list, but I got wrapped up in creating the web page and supporting script that calculates Date of Solar Longitude, and Solar Longitude on Date. Now it's avalailable on the web. Go see it at http://www.halcyon.com/gml/astro/ Let me know what you think. Gregg Lobdell gml@halcyon.com