Military/24-Hour Time Validation Rule

I am trying to create a validation rule that allows only military or 24-hour
clock time.

Is it's possible to have a validation rule that allows a number range of 00
to 23 for hours, and 00 to 59 for minutes? I've already created a
hour:minute format, but not sure if this is the best approach.

If it is possible, is it possible to set it up so that if the time is 1:34
PM it gets entered as 13:34 and not 1:34 which is really AM on the 24-hour
clock time.

Thanks in advance,
--
Natalie