How about someone who was raised on 12h time and has used it for 70 years? Sure, the math to convert is pretty easy, but why?

Ok right. I didn't know people were used to that.

You didn’t know about 300 million Americans?

I doubt that anyone knows 300 million people let alone that many Americans.

I'd guess that the very large majority of people don't know that americans use 12h time, no. Why would they?

It is a bit strange, like being surprised some countries drive on the left side. xkcd 1053 of course, but people are still allowed to be surprised when someone went their entire life without picking up a fairly common factoid.

I am grappling with this but I can't.

You did not know that large parts of the world default to 12h time?

This is absolutely NOT an American thing. I am not American and have never lived there. I am 58 years old, British and Irish, and lived a decade in Nigeria and a decade in Czechia. I have travelled widely around Europe and can get by in 6 foreign languages.

12h time in real daily life is more common everywhere I have ever been. Only minor subsections of humanity -- military people, maybe -- work on the 24h clock.

In the operating room, all the wall clocks are 12 hours but all records kept by humans are 24 hour time.

I am 38 and British and use 24hr clocks exclusively. This is also very common on the continent - the French nearly always use 24hr time for everything

Thinking on, yes, I think I'd noticed that. I love the country but I've never lived there full-time, though.

Indeed (French here). 12h time is still there in spoken language sometimes, but never in writing.

I learnt English as a kid with the 12h time, but UK friends nowadays say they tend to use 24h everywhere precision is needed (e.g. transport timetables) and less and less 12h in everyday chat. I was supposing USA was the same. Obviously not.

> UK friends nowadays say they tend to use 24h everywhere precision is needed (e.g. transport timetables) and less and less 12h in everyday chat.

That is the direct opposite of my personal experience.

I do not live in the UK; I live in the Isle of Man, nearby. I visit for work often, though. Yes, the 24h clock is used for things like transport times, but in daily life, written and spoken, it is basically always 12h. I would estimate 95-99% of the time.

I.e. boomers holding everyone else back again.

People who can't reliably subtract 12 from numbers. They're out there.

It's me! (But I solve it by using 24h for everything)

Americans. The U.S. has a lot of people who are unaccustomed to 24 hour time.

It’s the whole Anglosphere. We do it, as well as imperial measurements, to give the finger to Napoleon and his metric 10 hour long day system.

But 24-hour time is not decimal, isn't it what you guys like?

It’s not the whole Anglosphere.

24 hour time is used extensively in the UK. For example, all public transport uses 24 hour times here.

I knew for the imperial units but not this. This country ... let's say it always amaze me.

They use US customary, not imperial, they're slightly different sets of units.

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

> Some advocates of the customary system saw the French Revolutionary, or metric, system as atheistic. The president of an Ohio auxiliary of the Institute wrote that the traditional units were "a just weight and a just measure, which alone are acceptable to the Lord". His organization later went so far as to publish music for a song proclaiming "down with every 'metric' scheme".

Ooh that explains a lot.