|Excel doesn't recognize the "." as a Date separator.|
(This is by design.)
Are the dates all in one column?
(I have done this in Cell A1.)
If so, try this:
(I will assume 20.10.09 = 20 October 2009)
In an empty column, type the following formula:
(I have done this in Cell C1.)
=DATE(20 & RIGHT(A1,2), MID(A1,4,2), LEFT(A1,2))
That will convert it to a real Date.
(20 October 2009.)
If you use:
=DATE(RIGHT(A1,2), MID(A1,4,2), LEFT(A1,2))
You will get 20 October 1909.
Simply drag this formula down the list, to the end of your dates.
Select this Date List.
Right-Click the List.
Select your "." separated List.
Choose "Paste Special".
Select "Values", under "Paste".
(The other settings should be "None", under "Operation".)
(You can leave "Skip Blanks" and "Transpose" un-ticked.)
This will replace your Old List with an Actual Date List.
Format the List as: