>Hi Derk,
>
>There was a thread on this issue a year or so ago here on UT. The consensus seemed to be as follows: Fox can store dates from 01/01/0100 through 12/31/9999, but some of the date functions do not always work with dates prior to a certain time. For example, in my own admittedly non-rigorous testing with VFP 5.0a, GOMONTH(date, 12) returns " / / " for any date prior to 01/01/1752, but GOMONTH(date, 120) works with dates back to 01/01/1743.
>
>My understanding is that the Gregorian calendar replaced the Julian calendar in 1582, at which time several changes were made that mess up the "how many days between two dates" type of calculation for dates than span that year. So it's understandable why some of VFP's date calculations would not work for dates prior to 1582, but I don't know what the significance of 1752 or 1743 is.
>

Turns out that GOMONTH(date, 1200) works with dates back as far as 01/01/1653. So the significant factor seems to be that the result of the GOMONTH calculation has to be 01/01/1753 or greater.