In response to a query by Josh Williams: I have a simple BASIC program that will do this. It is based on equations published in "Practical Astronomy With Your Pocket Calculator" by Peter Duffet-Smith. I can e-mail you an ASCII copy of the routine if you'd like. TTFN Geoff +=====================================================================+ & Geoff Chester Albert Einstein Planetarium nasep007@sivm.si.edu & &=====================================================================& & "If you push something hard enough it will fall over" & & -- Fudd's First Law of Opposition & +=====================================================================+