I think there's some 'intelligence' built into Excel. But it's not your intelligence, but Microsofts. You can't do anything about it, I'm afraid.

I'm in Holland, so my computer with Excel 97 has dd-mm-jjjj format.
If I type 5-7 (July 5) it's interpreted as July 5, 2005 (current year). If I type 5-13 (which can't be dd-mm) it's interpreted als mm-yy (May 1, 2013).

So I suppose 7/05 is interpreted as July 5, 2005 (july-05) and 7/07 as July 7, 2005 (also July-05).
Try 7/32? That should be july 1, 2032, because it can't be July 32, 2005.

One solution would be to enter the full date, which can only be interpreted in 1 way: 7/1/05 for 2005 and 7/1/07 for 2007. Once understood, it will be shown according to the format you specified.

The other solution would be to format the field (column?) as Text. Then what you type in isn't interpreted/translated, but shown literally. Just enter Jul-05 and Jul-07 and it will be shown. But you can't do date calculations then.

Hope this helps.


Kees