Thank you to those who tried to help me with this frustrating problem.
After a lengthy process of trial and error and assistance from a
friend who is more computer-literate than I am, the cause has been found
Weird as it sounds, it was the way in which I had set the Vista default
*time* format in Control Panel > Regional and Language Options. I had
the time format set as HHmm -- although this was accepted by Vista, it
caused (for reasons that are totally inexplicable to me) dates entered
in Excel 2003 to be corrupt or not accepted as dates. It appears that
the problem does not occur when the default time format is set to HH mm
In Windows XP, the time format HHmm will not be accepted -- it must be
either HH mm or HH:mm. What a pity that Vista accepted it -- and caused
me (and others) to waste many many hours trying to solve the problem.
Can others replicate the problem? If so, it should be reported to
Microsoft as a bug.
> On Wed, 20 Jan 2010 23:08:11 +1100, Lindsay Graham
> <LDGraham@newsgroup> wrote:
>> I don't think it is an Excel problem. I have used dates and times
>> extensively in Excel 2003 and Windows XP (and their predecessors). I
>> never had any problems until I shifted to Vista. Date formatted cells
>> work fine in WinXP but, in the same Excel file, will not work in Vista.
>> I've been getting some help (although, so far, no solution) through an
>> Excel mailing list, and that led me to the language issue raised below.
>> Because that seems to me to be a Vista issue, I asked about it on this
>> I hope someone can help.
> As noted, you'd be better off posting to microsoft.public.excel.
> I noticed the same issue getting worse and worse in excel and
> definitely between office applications (e.g. copy a column from Access
> to Excel). The best solution, if you are getting the funky little
> green triangles in the corner of the cells and the exclamation point
> drop down is to select the cells in error and choose the appropriate
> fix from the menu, thereby correcting all cells.
> For more specific advice, see the excel newsgroup. They will be
> familiar with whatever troubles you, even if it only shows up in