Excel date format won't change

Quite strange. The lower cell is definitely not date but is text. If you expand that column, you will see that it will remains on left side. The dates are by default, right justified as the one above it. I entered one value down with CTRL + ; and was still able to format it. Since you said you have checked that the cell was pre-formatted to be date and only then you entered the short cut, I guess some thing is forcing the date entered via that short cut to appear as text

OK, has it anything to do with any option settings in Excel? Even if I try to reformat the cell using any other format, it just won't change...

I have had this problem for a long time and the only solution I have found is this.
1) (Save As) a Tab Deliminated.txt file.
2) Open New Excel
3) Open File and choose Tab Deliminated Option.
4) Go to each Date column and select it and chose Date DMY, MDY(Whichever) format.
5) Select Finish.
All dates should now format ok.

this doesnt work for me and I am having the same issue, its like the column which contains an export of data with both types of US and Uk dates in various formats doesnt listen to thing I want to do.

i tried to create new column, define the format in different formats and copy the values, nothing happens.

i tried a formula the attempt to convert it to text and one that attempts to convert it to date formats, nothing happens.

its literally just keeping the same format, data,layout, whatever I do :s

any ideas on this one?

See if this helps u
https://ccm.net/forum/affich-595248-text-format-to-date-month-year-on-excel#11

Could you put possibly put a sample file with the issue at some shared location like https://authentification.site and post back the link. In my test, only time I was not able to change the format was when the target cell was pre-formatted to be a text