Is there any way in which I can insert the date into a document automatically, but make the document still show that date when I open it a year later?
ie I have been looking at past correspondence files and find that each document shows today's date. If I want to check when it was created I have to look at the Document properties, but even that has changed in some cases, possibly because I had to have a disc replacement.
Yes, in many cases I am including the date in the file name nowadays.
From what I recall, you probably have the date formatted as "Today" or "System date", so that every time you open the document it will come up as Today. I haven't got Wordpro on my machine now, but I think you will find by looking in the Formatting area there are several ways of formatting the date field. Browse through it and I'm sure you will come up with the right date that will stay at the date you wrote the document.
As TonyV says, you seem to be inserting the system date. If you go to TEXT/ Insert Other/ Date & Time/ Date. In the Drop-down menu you can select "Date Created" which I imagine will remain constant. Hope this helps.