If someone says "Oct 19 at 12am", I suppose that means the first moment of the day, not the last. Time goes from 11pm to 12am to 1am. 11am to 12pm to 1pm.
12:00 noon isn't really am or pm. It's m; meridian.
12:00 midnight is sort of both am and pm; in the middle.
When the clock strikes twelve is the new day started.
Noon is infinitely small, infinitely short. The moment noon happens, it is past. So I suppose 12 noon is pm. And 12 midnight is am, and is the first moment of the day.
The day ends at midnight, and begins at midnight.
The day begins in the middle of the night.
The night doesn't begin in the middle of the day.
12:00 noon isn't really am or pm. It's m; meridian.
12:00 midnight is sort of both am and pm; in the middle.
When the clock strikes twelve is the new day started.
Noon is infinitely small, infinitely short. The moment noon happens, it is past. So I suppose 12 noon is pm. And 12 midnight is am, and is the first moment of the day.
The day ends at midnight, and begins at midnight.
The day begins in the middle of the night.
The night doesn't begin in the middle of the day.