That was my long-held view - until earlier today.
What about 1 second later?
0. 1 seconds later?
0. 0…1?
How much of the time represented by 1200 is midday and how much post?
I think it's only midday if it rounds to 12 to whatever accuracy one is using. So 12:00:00.001 is PM if you are really working to millisecond accuracy, but it is 12 noon to the nearest second.
What changed my mind was seeing 1200 not as an instant in time but a time interval: 1200 <= t < 1201. Midday (meridiem) is, in contrast, an instant. Every value of t other than 1200 is pm.
Comments
What about 1 second later?
0. 1 seconds later?
0. 0…1?
How much of the time represented by 1200 is midday and how much post?