Hi Will,
After you complete the SiteAssist Pro wizard, you can add any code you like to the calendar page to make it dynamic. The easiest way would probably be using PHP and some of the date functions it exposes.
Check out the date() and strtotime() functions especially.
date
strtotime
I also did a simple web search for 'php calendar' and several open source scripts popped up. You could implement one of those as well.
-justin