"Night and Day are variable (and thus somewhat meaningless) terms in regards to time. During the summer...it is still "bright as day" at 6:00pm. During the winter, it is "dark as night" at 4:00pm. This also of course varies by where on the earth you are...the closer to the poles you go, the longer these cycles become to the point where they are TOTALLY meaningless (daytime lasts for weeks, as does nighttime).

Add to that the fact that military operation can take place at ANY place (such as close to the poles) and at ANY time, regardless of the presence of "day" or "night", and you can see how in the military the concept of "AM" and "PM" at best is meaningless and could possible be confusing.

A 24 hour clock eliminates all of this."

Hoped this helped you find your understanding of military time.

It is pretty much to remove the AM/PM thing as mentioned above.

Think of an important comm coming through with 4PM on it, somehow misheard or misprinted.
Thats a 12 hour mistake that could cost lives

Thanks guys. Very helpful information, glad I know now!