Hi

Sounds to me like the data may actually currently be held as text
rather than as a numeric date (check this by amending the format via
FormatCellsNumber tab (xl2003 and below) or the Number section of
the Home ribbon (xl2007)Number tab and specify a custom format of dd
mmmm yyyy - if it doesn't change the data, then you have text values
rather than true date numerics).

Hence, what I would suggest is to select the column containing these
'dates' and go DataTextToColumnsDelimitedNextNext and choose an
Import Date Format of DMYclik Finish. (The TextToColumns option lives
on the Data ribbonData Tools section in xl2007). This will (or
should) convert the values to dates, in which case you can set the
desired format by the same process above. Excel then shouldn't change
them on editing the cell.

Richard


On Dec 29, 6:12 pm, alexc wrote:
I have a date format dd/mm/yy, but when I double click on it to change the
data, it changes to mm/dd/yy. How can I prevent this from happenning
Thank you