Error message - "The workbook you are pasting to uses a different date system"

[export9]

I am getting an error message when trying to copy a large amount of data and paste special values from one workbook to another.

Help! Is there a work-around?

The body of the text reads as follows: "The source workbook uses a different date system than the target workbook. Copying and pasting between these workbooks will causetheir dates to differ by approximately four years. Excel can convert the
dates so that their values match the date system in the target workbook. Learn about date systems"

It then only gives me two options: "Don't Convert" or "Convert". I tried both and both result in date-changes...they should remain the same!

 

[mole999]

you have one with 1900 and the other with 1904 (options), one allows negative times. you could convert one and all the dates will be out by four years, and then fix once to be able to use both