>VFP is designed to process dates from the 17th. century and later, only.

No longer correct, incidentally.

>The reason is that shortly before this - 1582, IIRC - there was the change from the Julian
>calendar to the Gregorian calendar. 10 days were omitted, to make Spring start, once again,
>on March 21. This can cause some confusion (which calendar to use?), and this probably
>explains the decision not to use dates before the 17th. century.

Of course, you have to then ask "in which country?" As you point out, some countries didn't make the switch until much later.