I have a word document which documents the date I have sent out an invoice to a customer and the days they are overdue. But is there a way of setting up a automatic calucation so that each time I open the word document, it calcuates the over due days based on the date of opening?

To see how to do just about everything you might want to do with dates in Word, check out my Microsoft Word Date Calculation Tutorial, at:
http://windowssecrets.com/forums/sho...ation-Tutorial
or:
http://www.gmayor.com/downloads.htm#Third_party
In particular, look at the item titled Calculate the # Days Difference Between Two Dates. Do read the document's introductory material.

As for the automatic calculation, Word won't do that without a macro, which is quite simple. Otherwise, you could just use Ctrl-A, F9, to update all fields in the document.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]