Here in Quebec, I would say that I took the 1643 train the other day (which I did). I imagine that in French they would say seize heures quarant-trois, but I am not certain.
The question is about describing the time when it’s on the hour with no minutes.
You’ve asked for the time, and you got a number. There is only one 1700; only one seventeen. What other time could it mean?
The question is not about proposing some hypothetical non-ambiguous usage. It’s about actual colloquial usage in English dialects (or other languages). I know that some languages would just say “seventeen”. But so far as I know, that’s not common usage in any dialect of English.
I was responding to manson1972 in that post, not the OP. That’s why I quoted manson1972 and replied under the quote. He did in fact call it “ambiguous”, which it is not, unless we’re using some other definition of ambiguity. There is only one interpretation for what time it could be.
I’m not sure what you are trying to prove. Speaking a language isn’t about using non-standard expressions and then relying upon the listener to go through some deductive process about possible meanings. The fact is, if an English speaker asked you the time and you replied “Seventeen”, their reaction would be something like “Huh? I didn’t ask you for your age.”
Also, I’m not proposing anything. I’m answering the question. I am an English speaking American. The reason you probably don’t hear people refer to time like that is because the vast majority of Americans do not use the 24 hour clock. I use it exclusively.
This statement is false. BBC Radio is confusing all of their listeners as well? Maybe it’s just you who are confused.
You use it in what context?
General conversation about time. When things open or close, when things are scheduled, etc.
I’m not the outlier here. Several other posters have agreed to hearing it used without the “hundred”.
Doctor: “When did you last have sex?”
Patient: “2015”
Doctor: Looks at watch - “Wow! It’s only 2100 now, you must have come straight here.”
Don’t!! You’ll trigger a “Two-thousand fifteen” versus “twenty fifteen” debate!
Can you cite any other examples of English speakers communicating this way? I think the BBC’s usage in that World Service context with “GMT” appended is atypical. Would a BBC newsreader say a time this way? I’m open minded, but frankly skeptical - I’ve lived my whole life in the U.K. and U.S. and never come across it. That is to say, native English speakers for whom this kind of exchange would be colloquial:
“What time shall we meet at the pub?”
“Nineteen”
I just reread the thread. No, they haven’t.
I’m done wasting time with you. You’re being intentionally obtuse. Here are two posters agreeing with me. Hell, one even refers to mainland Europe–where I currently live, and which you’ve already mentioned. So, that’s not unknown to you. When I talk to people around my town, around Germany, and around mainland Europe, I talk to them in English. As they are often store clerks, gas station attendants and mechanics, veterinarians, hotel workers, airline agents, my landlord, etc., I often have conversations involving a question of what time something will occur. Often enough, if not exclusively, it’s simply the number. No “hundred”.
Saw your other post before this one. See my response above for answers to this question. The US doesn’t count, because you are just as likely to confuse someone by saying “Seventeen Hundred” as you are “Seventeen”.
Also, I was just in Gibraltar, an English speaking country in mainland Europe. I wish I would have seen this question a month ago. I would have paid more attention to usage.
And yes, your conversation about the pub is common with native English speakers whom I interact with daily. Either 19 or nineteen hundred. “Seven” would also be normal. However, I am reluctant to use that as an example, because the people I’d go to a bar with are other military people, and the OP asked about nonmilitary people.
A recent example would be me asking my landlord today what time he wanted to meet. Fourteen or fifteen? He speaks fluent English as a second language. He answered fourteen with no confusion. Store clerks often tell me the store closes at nineteen, if I ask. Etc.
Yes in our international financial sector English, maybe most of us are not the native speakers but many are, but to avoid the ambiguity it is always said 17, etc.
the new americans who join sometimes try to stick with the oclocks but eventually get used to it.
Of course in French I would say 17 hour.
The guy who sells booze right before the bridge. 
When Jonathan Chance spoke of continental Europeans, I assumed that he was speaking about non-English speakers. And as someone who grew up in the U.K., I can tell you that cite of the BBC World Service saying “13 GMT” does not reflect colloquial usage.
In any event (from your other response) I think we’re getting somewhere. What you are saying is that among the English-speaking expat community in Europe it’s common to say just “thirteen” “fourteen” etc. for on-the-hour times when speaking English, consistent with usage in other European languages.
But you acknowledge that this is not normal usage in the U.K. or the U.S., right? If you were asked the time in the U.K. or the U.S. and replied just “seventeen” you would get a puzzled look, and it would not be clear that you were stating a time at all. “Seventeen hundred [hours]” would be unusual and would mark you as military, but it would at least be understood that you were responding with a time.
In Thai we use either a 24-hour clock or divide the day into six-hour periods, so 21:00 would be either ‘twenty-one clock’ or ‘three evening’ but never ‘nine.’ (Mechanical clocks show ‘9’; digital clocks have 24- and 12-hour modes but no 6-hour mode. Yet when the clocks read 9:00 (in the evening) it is never called ‘9’, always ‘3 evening’ or ‘21 clock.’)
In practice, appointments are not resolved as finely as an hour. ‘Bai bai’ means ‘twoish in the afternoon, maybe three or four.’ ‘Sai sai’ means ‘fourish or five or so.’ ‘Meut meut’ means ‘after dark.’ ‘Chao chao’ means 7:30 a.m. or thereabouts, unless the first ‘chao’ is emphasized with a high rising tone — then we’re talking about leaving the house before dawn.