|The whole point of using the 24 hour clock is that there are not supposed to be any punctuation marks! |
Not in my experience.
If you really really really must have the data input without the colon then
a work around is a Custom Format:
Try this: 0\:00
BUT, BE WARNED the data you enter is NOT a Time entry, it will
display as time, but it is only a number and you can not do Time calculations.