Bizarre Excel Copy/Paste Date Issue

[Rob]

I'm working on 2 xls Excel 2000 files (with all Office Updates and Windows
Updates applied on this WinXP PC). I'm copying a date from a cell in A.XLS
and pasting it into B.XLS. Both cells are formatted as dates. I copy the
1/1/1999 from A.XLS but when I paste it into B.XLS, it shows up as 1/1/1994.
There are NO formulas involved and I have auto-calculation ON. They are not
text, they are true date entries.

I've never seen anything like this and wouldn't know where to look for help
on this except for here.

Any suggestions greatly appreciated.

-Rob

 

[Bernie Deitrick]

Rob,

One workbook is using the 1904 date system: dates in Excel are just formatted numbers, the number
being the count of days since an arbitrary baseline: either 1/1/1900 or 1/1/1904. This baseline can
be set on a workbook by workbook basis, so it seems that A.XLS is using the 1904 date system.

Change it by using: Tools / Options Calculation Tab, uncheck "1904 date system"

HTH,
Bernie
MS Excel MVP

 

[Dave Peterson]

Just to add to Bernie's response...

One workbook was using a base year of 1900 and the other was using 1904.
(tools|options|calculation tab|1904 date system)

One way to add those four years back is to find an empty cell, put 1462 into
that cell.

Copy that cell.

Select your range that contains the dates. Edit|PasteSpecial|click Add (in the
operation box).

You may have to reformat the cell as a date (mine turned to a 5 digit number).
But it should work.

You may want to do it against a copy...just in case.

(I'm not sure which one you'll fix. You may want to edit|pastespecial|click
subtract.)

Most windows users use 1900 as the base date. Mac users (mostly??) use 1904 as
the base date.