[goialoq]

AM means "before noon". PM means "after noon"

12:00 noon is neither AM nor PM, and there'se no confusion.

The real question is why is the hour after midnight 12:01-12:59 AM.

Anyway, the real answer is that 0/12 and 13/1 are partial branch cuts and that "12" is used because "0" is awkward for mundane reasons, but retains some of its "0-ness"

https://en.wikipedia.org/wiki/Branch_point

[mark-r]

I'm not disagreeing that "noon" or "midnight" are less confusing, I'm simply saying there shouldn't be any ambiguity about 12AM or 12PM in the first place.

Any potential for confusion results from an ancient decision to designate noon/midnight as 12:00. If they had simply made them 1:00 instead then there'd be no trouble today.