I did some Googling and it looks like Word does have a table formula feature. However it looks pretty simple. I couldn't get it to automatically changed the referenced cell when I copy/pasted like it does in Excel.
The formula feature is located at Table Tools -> Layout -> Formula.
http://office.microsoft.com/en-us/word-help/use-a-formula-in-a-word-table-HA102329800.aspx
Maybe you could try a Calendar Wizard? New -> Office.com Templates -> Calendar? I've used that a couple of times before and it's made me some nice looking calendars. They don't dynamically update, but you can tell it exactly how many pages to generate for you.
Hope that helps.