I have some data that was sent to me that needs to be manipulated.

The data includes date/times in a column that I want to reformat into the
date/military time format.

The original spreadsheet had the date time format as custom. When I try to
reformat the cells, the appearance does not change. That is to say that, for
example, a 2:00 PM time still appears that way instead of as 1400.

Any idea why the reformatting of the cells does not appear to be catching on?

TIA for any input.