Correct way to display military time

I think you are asking about the 24 hour clock. How it is displayed would depend on the country your asking about:

Most countries display as 13:00 for example. See:

https://en.wikipedia.org/wiki/24-hour_clock

The US, Canada and other allied English speaking counties omit the hour:minute separator when using military time. So 13:00 would be 1300.

24-Hour Time is not "military time."

You can customize the time and date settings in Language and Region system preferences. However, the menu bar clock has never followed those settings.

military-time wrote:

It bugs me (a bit) that you folks do not display correct military time. As an example you display 9:00 AM as 09:00. The correct way to display it would be 0900 without the :

FWIW, this is a users forum so "you people" are not here. You can send Apple Feedback about their method of displaying a 24 hr clock here: Apple Feedback.