# 24 hour clock **URL:** \ **Category:** Factual Questions\ **Created:** [November 9, 2018, 5:18pm UTC](https://boards.straightdope.com/t/24-hour-clock/824253 "2018-11-09T17:18:35Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Paintcharge](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/paintcharge/32/7946_2.png) [@Paintcharge](https://boards.straightdope.com/u/Paintcharge)\ **Post date:** [November 9, 2018, 5:18pm UTC](https://boards.straightdope.com/t/24-hour-clock/824253/1 "2018-11-09T17:18:35Z")
When non-military people use the 24 hour clock, how do they say, out loud, 17:00? Is it seventeen hundred? seventeen o’clock? ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [November 9, 2018, 5:25pm UTC](https://boards.straightdope.com/t/24-hour-clock/824253/2 "2018-11-09T17:25:09Z")
Not a military person, but I’m fairly sure it’s seventeen hundred. ---
**Author:** ![BrickBat](https://avatars.discourse-cdn.com/v4/letter/b/ac91a4/32.png) [@BrickBat](https://boards.straightdope.com/u/BrickBat)\ **Post date:** [November 9, 2018, 5:27pm UTC](https://boards.straightdope.com/t/24-hour-clock/824253/3 "2018-11-09T17:27:14Z")
It’s used where I work. 17:00 is pronounced “Seventeen-hundred” by most, if not all. For whatever reason, 0100 to 0800 are pronounced "Oh ( number hundred… “Oh-five hundred” ) but with 0900 the “oh” is omitted. ---
**Author:** ![Dobbs](https://avatars.discourse-cdn.com/v4/letter/d/5f9b8f/32.png) [@Dobbs](https://boards.straightdope.com/u/Dobbs)\ **Post date:** [November 9, 2018, 5:37pm UTC](https://boards.straightdope.com/t/24-hour-clock/824253/4 "2018-11-09T17:37:02Z")
‘17-hundred hours’ is what I’ve said and heard back in the day, as well as ‘20-hundred hours’(as odd as it sounds). Sometimes ‘17-hundred local’ or specify the time zone when talking across time zones. Not on the hour would be, say, ‘17-13’, with context providing that it was the time, with ‘local’, ‘Zulu’ or other time zone as needed when speaking. Written would be ‘1713 hrs’. I dunno why we didn’t spell out ‘hours’, it’s just the way it was. ---
**Author:** ![Bear\_Nenno](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bear_nenno/32/3358_2.png) [@Bear\_Nenno](https://boards.straightdope.com/u/Bear_Nenno)\ **Post date:** [November 9, 2018, 5:51pm UTC](https://boards.straightdope.com/t/24-hour-clock/824253/5 "2018-11-09T17:51:11Z")
> [@Paintcharge](#): > > When non-military people use the 24 hour clock, how do they say, out loud, 17:00? > > Is it seventeen hundred? seventeen o’clock? I just say seventeen. There is no need for “hundred” or “oclock” when it’s clear you’re talking about time. And since no numbers are repeated, there is no need for a.m. or p.m. When does that store open? _I think it opens around seven or eight_. When does the train leave? _The train will depart at twenty-one thirty._ Do you want to meet at seventeen or eighteen? _A little after nineteen is better for me_ With that said, saying “hundred” is also common. “O’clock” is right out. ---
**Author:** ![spifflog](https://avatars.discourse-cdn.com/v4/letter/s/c5a1d2/32.png) [@spifflog](https://boards.straightdope.com/u/spifflog)\ **Post date:** [November 9, 2018, 6:36pm UTC](https://boards.straightdope.com/t/24-hour-clock/824253/6 "2018-11-09T18:36:16Z")
In my 30 plus years in the military: 95% of the time it was “seventeen hundred” 5% of the time “seventeen hundred hours” 0% of the time anything else including just “seventeen” or “seventeen o’clock.” I’ve never once heard either of those two. Now if we could just solve “over and out.” ---
**Author:** ![Gatopescado](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gatopescado/32/5711_2.png) [@Gatopescado](https://boards.straightdope.com/u/Gatopescado)\ **Post date:** [November 9, 2018, 6:39pm UTC](https://boards.straightdope.com/t/24-hour-clock/824253/7 "2018-11-09T18:39:51Z")
> [@spifflog](#): > > Now if we could just solve “over and out.” And who is Roger Wilco? ---
**Author:** ![Slash1972](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/slash1972/32/6461_2.png) [@Slash1972](https://boards.straightdope.com/u/Slash1972)\ **Post date:** [November 9, 2018, 6:41pm UTC](https://boards.straightdope.com/t/24-hour-clock/824253/8 "2018-11-09T18:41:34Z")
> [@Bear\_Nenno](#): > > I just say seventeen. There is no need for “hundred” or “oclock” when it’s clear you’re talking about time. And since no numbers are repeated, there is no need for a.m. or p.m. > > When does that store open? > _I think it opens around seven or eight_. > > When does the train leave? > _The train will depart at twenty-one thirty._ > > Do you want to meet at seventeen or eighteen? > _A little after nineteen is better for me_ > > With that said, saying “hundred” is also common. “O’clock” is right out. “What time is it?” “Seventeen” Seems ambiguous. ---
**Author:** ![kenobi\_65](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kenobi_65/32/13178_2.png) [@kenobi\_65](https://boards.straightdope.com/u/kenobi_65)\ **Post date:** [November 9, 2018, 6:42pm UTC](https://boards.straightdope.com/t/24-hour-clock/824253/9 "2018-11-09T18:42:12Z")
i often listen to the BBC World Service radio news. The announcer who previews upcoming programs at the top of the hour often gives the time as Bear\_Nenno describes: “Coming up at 7 and 13 GMT…” ---
**Author:** ![Dobbs](https://avatars.discourse-cdn.com/v4/letter/d/5f9b8f/32.png) [@Dobbs](https://boards.straightdope.com/u/Dobbs)\ **Post date:** [November 9, 2018, 6:52pm UTC](https://boards.straightdope.com/t/24-hour-clock/824253/10 "2018-11-09T18:52:11Z")
> [@Gatopescado](#): > > And who is Roger Wilco? His full name is Roger ‘I understand and will comply’ Wilco. ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [November 9, 2018, 6:56pm UTC](https://boards.straightdope.com/t/24-hour-clock/824253/11 "2018-11-09T18:56:54Z")
NON-military people pronounce “17:00” as “five o’clock”. Which is fairly unambiguous if you think about civilian business hours. ---
**Author:** ![Nava](https://avatars.discourse-cdn.com/v4/letter/n/da6949/32.png) [@Nava](https://boards.straightdope.com/u/Nava)\ **Post date:** [November 9, 2018, 7:20pm UTC](https://boards.straightdope.com/t/24-hour-clock/824253/12 "2018-11-09T19:20:15Z")
> [@DPRK](#): > > NON-military people pronounce “17:00” as “five o’clock”. Which is fairly unambiguous if you think about civilian business hours. If your business is very local AND you’re not using a 24h clock. One of my first jobs involved tracking purchase orders; I had to explain that giving me the phone number for suppliers in Honk Kong, Japan and Australia wasn’t going to be very useful, could I have a fax or email? ---
**Author:** ![Jonathan\_Chance](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jonathan_chance/32/701_2.png) [@Jonathan\_Chance](https://boards.straightdope.com/u/Jonathan_Chance)\ **Post date:** [November 9, 2018, 8:05pm UTC](https://boards.straightdope.com/t/24-hour-clock/824253/13 "2018-11-09T20:05:59Z")
A very American question. In my experience in Europe and with Europeans on the continent there’s no ‘hundred’ bit. It’s just whatever the hour is. Ten, fifteen, twenty-two or whatever. ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [November 9, 2018, 8:22pm UTC](https://boards.straightdope.com/t/24-hour-clock/824253/14 "2018-11-09T20:22:56Z")
> [@Jonathan\_Chance](#): > > A very American question. In my experience in Europe and with Europeans on the continent there’s no ‘hundred’ bit. It’s just whatever the hour is. Ten, fifteen, twenty-two or whatever. Or is it a difference between English and non-English speakers? In my experience in either in the U.K. or the U.S. it would be quite odd so say just “thirteen” etc for any hour greater than twelve. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [November 9, 2018, 8:23pm UTC](https://boards.straightdope.com/t/24-hour-clock/824253/15 "2018-11-09T20:23:44Z")
I´ve a horrible feeling that I only use the ´hundred´term for hours 13 and above. I think maybe I use O´clock for hours 1 to 12 (and probably ´midnight´for hour zero) ---
**Author:** ![cochrane](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cochrane/32/10441_2.png) [@cochrane](https://boards.straightdope.com/u/cochrane)\ **Post date:** [November 9, 2018, 8:26pm UTC](https://boards.straightdope.com/t/24-hour-clock/824253/16 "2018-11-09T20:26:49Z")
> [@Gatopescado](#): > > And who is Roger Wilco? “We have clearance, Clarence.” “Roger, Roger. What’s our vector, Victor?” ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [November 9, 2018, 8:28pm UTC](https://boards.straightdope.com/t/24-hour-clock/824253/17 "2018-11-09T20:28:39Z")
> [@cochrane](#): > > “We have clearance, Clarence.” > “Roger, Roger. What’s our vector, Victor?” Due East, Duane. ---
**Author:** ![kenobi\_65](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kenobi_65/32/13178_2.png) [@kenobi\_65](https://boards.straightdope.com/u/kenobi_65)\ **Post date:** [November 9, 2018, 8:34pm UTC](https://boards.straightdope.com/t/24-hour-clock/824253/18 "2018-11-09T20:34:50Z")
> [@Riemann](#): > > Or is it a difference between English and non-English speakers? In my experience in either in the U.K. or the U.S. it would be quite odd so say just “thirteen” etc for any hour greater than twelve. See my post above, about usage on the BBC radio service; I have no idea how common or not that usage is, generally, among people in the U.K. In my experience, relatively few Americans really use the 24-hour clock notation, with or without “hundred.” ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [November 9, 2018, 8:38pm UTC](https://boards.straightdope.com/t/24-hour-clock/824253/19 "2018-11-09T20:38:16Z")
> [@kenobi\_65](#): > > See my post above, about usage on the BBC radio service; I have no idea how common or not that usage is, generally, among people in the U.K. I’m British. That BBC usage is unusual. Bear Nenno is evidently German? I know it’s common in continental Europe, but I’m not aware of any English dialect where it would be colloquial to say just “seventeen” for 5pm. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [November 9, 2018, 8:40pm UTC](https://boards.straightdope.com/t/24-hour-clock/824253/20 "2018-11-09T20:40:19Z")
On those occasions when I do use it properly, I probably have to explain that by “15 thirty” I mean half past three in the afternoon, so based on my very limited sampling, I might say there´s less than 50% uptake of 24 hour notation in the UK. This does open up some opportunities for confusing people by saying things like “9 O clock in the afternoon” or “2 O Clock in the evening” [Next page](https://boards.straightdope.com/t/24-hour-clock/824253.md?page=2)