Hi Joe:
It looks like some body has put a hex on your computer ... kidding aside, I can think of two possibilities
the source area (from where the copy has been made, is a formula involving the date function using the year, month, and day as parameters, or using the today() function, which gives the current system date as the system knows it -- so
1) in the copied to location, there may be different parameters resulting in a different date at the copied to location;
2) the system date in the source system and the copied to system may be different, thus resulting in different date displays,
and of course among other things, it can also be a combination of both of the things mentioned above.
HTH
Yogi Anand
ANAND Enterprises (broken link)