In the countries I’ve lived in and been to, they might not specifically say “a.m.” or “p.m.,” but rather use “in the morning,” “in the afternoon,” or “in the evening,” so, depending on what you’re asking, “5 in the evening” is quite usual colloquially. Official schedules I remember seeing primarily in 24-hour time, but in conversation, both systems are used. (I’m thinking Poland, Hungary, Germany, France, Croatia, etc., mainly European countries here.) Even in British English, you’ll see the 24 hour clock used, and if you listen to BBC News, you’ll hear stuff like “fourteen hundred hours.” In the US, I rarely see the 24-hour clock used, and when people see that my phone or computer or whatnot is set to 24-hour time, they ask me if I’ve been in the military, as it’s still seen as “military time” here.
As far as I’m aware, the 12-hour analog clock dial is pretty well known around the world, and particularly in Europe. That points toward an evolution from 12-hour segmentation to a full 24-hour count rather than the other way around.
Powers &8^]