Why do people write/say 12PM and 12AM? This is, by definition, contradictory. It can only be 12 midday or 12 midnight.
Ante Meridian is Latin for "before midday" so it can’t be 12 AM since at 12.00 it is no longer before or after midday. The same is true for PM (Post Meridian, Latin for "after midday").
Ante Meridian is Latin for "before midday" so it can’t be 12 AM since at 12.00 it is no longer before or after midday. The same is true for PM (Post Meridian, Latin for "after midday").