Yes, if it behaves that way for you, it's a bug. Perhaps you can tell us
which version of Excel you are using?

For the rest of the world, we can custom format as hh:mm and still type in a
number as 0.75 or 6:00 PM. It will still display as 18:00, but doesn't
constrain the format in which we enter the number, nor does that format
contrain the value which we can enter.
--
David Biddulph

Archimedes' Lever wrote:
On Thu, 30 Apr 2009 09:13:55 +0100, "David Biddulph" <groups [at]
biddulph.org.uk wrote:

If you want to use 12 hour format, then of course you need to
include the AM or PM. That's what 12 hour format is.

As I said in the part of my message which you snipped, data
validation and cell display formatting are two separate unrelated
features of Excel. Data validation can constrain the numbers that
it will allow you to store in the cell. The format in which you
choose to display the number is a separate matter.


The only exception, then, is if one chooses "custom" as the cell
format, and sets that string to "hh:mm". Maybe it is a bug. ;-)

That is why my cells would not accept any other input. After
choosing one of the given "time" formats for cells, it works fine.
Apparently my "custom" setup also forces a specific input mode, which
ends up being a type of validation.