A calendar that comes with most operating systems shuld be more than adequate. Of course the more bells and whistles may require someones opinion such as Aragorn on this board you may want to e-mail him directly.
I use a program called "Aquarium Manager". It is a shareware program that I found a long time ago. It is basically a glorified spread sheet, with graphs and some other bells and whistles. If you want I can see if I can find the installation program for it. Email me if you are interested.
Thanks everyone. I went to About saltwater aquariums and checked thier database for programs. I found 3 or 4 good looking programs. If anyone is interested just e-mail me.