AM is ante meridian and PM is post meridian. It's referenced to the prime meridian through Greenwich UK. If the sun is to the east of the line (ie. Before noon where it is vertical) it's before (ante) the meridian. If it's after (post) noon it's after the meridian. It's all outdated but that's how time works.

[–] KISSmyOSFeddit@lemmy.world 7 points 5 months ago (4 children)

12 pm isn't past noon, it's noon.
12 am is past noon just as much as it is before noon.
So for 12 o'clock, choosing am or pm is arbitrary convention.
So it would make more sense to reverse them, to get a consistant row that starts with 1:
1 am, 2 am, 3 am, 4 am, 5 am, 6 am, 7 am, 8 am, 9 am, 10 am, 11 am, 12 am, 1 pm , 2 pm , 3 pm , 4 pm , 5 pm , 6 pm , 7 pm , 8 pm , 9 pm , 10 pm , 11 pm , 12 pm

[–] ChanSecodina@sh.itjust.works 12 points 5 months ago

Not to defend 12hr time because it’s dumb as a bag of bricks, but 12:45pm is definitely past noon and having the time go from 12:00am to 12:01pm would be way too silly. Also, you can think of the moment between 11:59:59.999999~ as just before noon and 12:00:00.0000000001 as the first fraction of a second after noon if it helps.

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