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How should one say times aloud in 24-hour notation?

I was wondering if you could help me out with a matter that is bugging me.

Do you think it is wrong to refer to 18:00hs as "eighteen hours" while reading a time-table in a 24-hour clock country?

I mean, is it really necessary to convert the 24-hour clock times to 12-hour clock in order to speak proper English?

I had an argument yesterday regarding this issue, because someone was trying to correct me, as he was expecting to hear 6 PM instead of the way I was reading it (eighteen hours).

Doesn't it eventually depend on your situational context?

It's not the same case for a 24-hour clock European citizen traveling to England than the other way round. If going to England, I should try to adapt to the local system, since I know they are 12-hour based and they may not understand me if I start talking in 24-hour clock.

But if an English person goes to a country with a different time setting (24-hour clock based), the situation is different. Because times will be written in 24-hour clock formats, time-tables will be printed in 24-hour clock formats, etc. He will need that skill in order to fit in. He should be able to understand that 18hs (or eighteen hours) refers to 6 PM, and in that context, not even an English native speaker, IMO, should be in position to tell anyone that "eighteen hours" is wrong.

Since mine is a 24-hour clock based country, would you consider it wrong, then, for someone to read a time-table in this fashion?

Here is an interesting article on how many Europeans, for example, that live in a 24h-hour clock country (like mine), refer verbally to their 24-hour based times when expressing themselves in English.

In written form they just write the time in their local 24-hour form (of course), but when speaking, however, they might use either the 24-hour-clock number, or a 12-hour-clock number followed by the phrase (in local lingo) "in the afternoon" (we also use that form but informally) —so at 3pm, they may say "it's fifteen o'clock" (or, more usually, just "it's fifteen") or they might say "it's three in the afternoon."

Full article: http://www.reidsguides.com/t_pt/t_pt_timezones.html

marked as duplicate by FumbleFingers, Mehper C. Palavuzlar, simchona, Monica Cellio, Marthaª Dec 1 '11 at 23:03

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If the convention in your country is to use a 24-hour clock then you would be perfectly justified to say to an English-speaking visitor "dinner is at nineteen hours" if this is a direct translation of how you would express the time in your native language. Your guest may look a little confused but should quickly understand that you meant, in her terms, seven pm.

Many English speakers are familiar with 24-hour clock notation from watching war movies and trying to comprehend bus timetables. But you may be better understood if you said "nineteen hundred hours". Strictly speaking, "nineteen hours" sounds to an English speaker more like a duration ("the flight took nineteen hours") than a time ("the flight lands at nineteen hundred hours").

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    It seems churlish of the visitor to insist that Eduardo phrase the time in a manner familiar to the visitor. But for Eduardo to say "eighteen hundred hours" instead would be a reasonable accommodation. +1 – Gnawme Dec 1 '11 at 22:26
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    So you really say "eighteen hours" and not "eighteen o'clock"? – GEdgar Dec 1 '11 at 22:34
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    @GEdgar, if you're asking me what I would say, the answer is neither of those. If I was asked to read aloud "18:00" I would say "eighteen hundred hours" or "six pm". I wouldn't say "eighteen hours" but would understand if someone else said that. I would never say "eighteen o'clock" and would probably correct a non-English-speaker who did. – Stuart Allen Dec 1 '11 at 22:38
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    @Gnawme, I would totally agree with you except for the hundreds accommodation. Our natural way of reading the time would be in this case "eighteen hours" instead of the hundreds, for the same reason I expressed on my previous message. Basically because adding the "hundreds" is totally unnatural to us, despite our use of the 24-hour clock. We just read the hour followed by the minutes when necessary. So, "eighteen hours" would be much closer to our reality than that hundreds accommodation. – Eduardo Dec 1 '11 at 23:00
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    @Snubian, thanks for your answer. You are right, but ambiguity between a time interval and a time reading would be a reasonable price for this, especially considering that in Spanish, that ambiguity exists every time we mention a time. i.e., "10 horas" can mean 10 o'clock in the morning, or a ten hours period of time. – Eduardo Dec 1 '11 at 23:23

Usually when I see such times written, they are written as 1800h, without the hour-minute colon separator. Even when they have a colon, the time is pronounced as Eighteen-hundred. The time 0900 I have heard pronounced as Oh-nine-hundred.

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    In a military context, it is always pronounced Oh-nine-hundred hours. And getting up early is sometimes referred as Oh-Gawd-hundred hours – TimLymington Dec 1 '11 at 21:43
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    @TimLymington -- I've always heard of a time in the wee hours referred to as oh-dark-thirty. – Gnawme Dec 1 '11 at 22:17
  • Hi, sorry for the previous post, I just hit enter for a line-feed and it posted the message. Going back to the reply, I was trying to say that we are not at all in a military context. It's just that the country (as many others) uses the 24-hour clock format as it's official system. Every schedule, every time-table is always specified this way. I find speaking of hundreds too military-like (we don't speak like that at all, and however we do use the 24-hour clock). It would be much more natural for us to say "eighteen hours" for 6 PM, or "eighteen thirty" for 6:30 PM. – Eduardo Dec 1 '11 at 22:51
  • @FrustratedWithFormsD, not using the colons between hours and minutes is possible, but exceptional and limited to very specific situations and contexts, i.e. I may have seen that format on some flight reservations, but times here as well as any other 24-hour clock country are expressed the very same way as yours, that is HH:MM (just without the need of an AM or PM indicator as its implicit by the time value). – Eduardo Dec 1 '11 at 23:36
  • @TimLymington Military use does not, in fact, always phrase it as Oh-nine-hundred hours. The U.S. Navy uses "Oh-nine-hundred," and for the first example, "Eighteen hundred." The "hours" part is not used if you're Navy. – John M. Landsberg Mar 6 '13 at 8:30

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