[Denvercoder9]

No, we just don't use AM/PM. In written language, the 24 hour format is used exclusively. When the 12 hour format is used in spoken language, we either leave it out entirely when clear from context, or use "in the morning" vs "in the evening".

So noon is "12 in the morning", which is an hour after "11 in the morning"; and midnight is "12 in the evening", which is an hour after "11 in the evening".

[thaumasiotes]

That's not really compatible with your comment about the US. By your own description, you do exactly the same thing that the US does,† but it's only strange when the US does it?

† That is, you follow 11:00 PM with 12:00 AM, and you don't actually refer to "AM" or "PM". Both of those are normal US practice. You are different in the use of 24-hour formats in writing, but that has no bearing on the question of whether the hour following 11 PM is 12 AM; you just assured me that that's true in both countries.

[Denvercoder9]

In your comparison, we follow 11:00 PM with 12:00 PM, not 12:00 AM.

[thaumasiotes]

So the day begins at 1:00 AM rather than midnight?

[Denvercoder9]

No, the day begins at midnight, we just call it 12:00 PM.