No, it's neither 12AM nor 12PM. Those are improper terms.
The abbreviations AM and PM stand for Ante Meridiem (incorrect: the correct word is "Meridian") and Post Meridiem (incorrect; "Meridian" is correct), respectively. The terms ante and post mean before and after. The term meridiem (incorrect; "Meridian" is correct) refers to when the sun is at the middle of its arc across the sky.
Nominally the sun is at its meridiem (incorrect; "Meridian" is correct) at noon. Since it is *at* its meridiem this is neither before nor after the meridiem (incorrect; "Meridian" is correct) . It *is* the meridiem (incorrect; "Meridian" is correct) .
Likewise, midnight is neither 12 AM nor 12 PM. It is equally far from both. It is simply 12 midnight.
The military clock is better than the civilian clock for many reasons. One is that (it) eliminates the complexity of specifically accounting for whether a time is before of ("or") after midnight. On the military clock noon is read as 1200 hours, and midnight is read as 2400 hours.
0
12am is midnight. 12pm is noon.
10 AM
Ante and post meridium, meaning before and after noon respectively. This means 12am (midnight) to 11:59 just before noon is am, and the other 12 hours is pm.
24
12pm is daytime (noon) 12am is nighttime.
12am/pm in Chicago 9am/pm in Juneau
12am to 4pm is 16 hours.
12 am or 12 de la noche las doce de la noche medianoche
Noon is 12:00 p.m.
Thursday 12 am
After midnight it is 12 am.