Talk:12-hour clock

What links here

• 1 A.M., 2 A.M., 3 A.M., 4 A.M., 5 A.M., 6 A.M., 7 A.M., 8 A.M., 9 A.M., 10 A.M., 11 A.M., 12 A.M.,
• 1 P.M., 2 P.M., 3 P.M., 4 P.M., 5 P.M., 6 P.M., 7 P.M., 8 P.M., 9 P.M., 10 P.M., 11 P.M., 12 P.M.,

..these should all link here. In ictu oculi (talk) 23:44, 15 March 2019 (UTC)

Incorrect statement added to "Clock system" table

In this edit Woodstone added the phrase "shown as start of next day" to the entry for 24:00. I'm not sure what the heading of this table might have been in the past, but now it is "Clock system", which is a rather general term, and certainly does not limit the information to what would be seen on the face of a digital or analog clock. It could apply to any textural display of time-of-day, such as books, timetables or the like. In such a setting, "24:00" is sometimes encountered, and it means that the midnight is being treated as part of the day that is ending, rather than part of the day that is beginning. The statement "shown as start of next day" is a confusing statement. If it's displayed as "24:00" it isn't treated as the start of the next day. If it's displayed as "00:00" then it's covered by the first line in the table. Jc3s5h (talk) 15:51, 29 June 2019 (UTC)

I have not added that line, but reverted its removal after it had been there for a very long time. It is in the column for the 12-hour clock, which does not have a separate expression for midnight at the end of the day. Instead, in that clock system, the end of a day is always expressed as the start of the next day. That is valuable information and answer to lots of discussion. Also it completes the day and the comparision to the 24-hour system. −Woodstone (talk) 16:12, 29 June 2019 (UTC)

The section "Confusion at noon and midnight" provides several reliable sources that indicate midnight can mean either the beginning or end of the day, or which disagree with one another. The Associated Press Style Book (2008) is cited; I will update it to the latest edition, 2019. It directly contradicts your proposition:

midnight Do not put 12 in front of it. It is part of the day that is ending, not the one that is beginning.

Jc3s5h (talk) 16:49, 29 June 2019 (UTC)

The table shows variants of representation. So mention of representing midnight at the the end of a day as the beginning of the next day is warranted.−Woodstone (talk) 14:36, 1 July 2019 (UTC)

The variant where midnight is thought of as the beginning of the day is already listed at the beginning of the table. I object to the addition, it is confusing. Jc3s5h (talk) 14:55, 1 July 2019 (UTC)

You keep calling it an addition, but the phrase has been in the article for many years. It is there because it reflects the real confusion that exists about what exactly are 12 am and pm in the 12-hour clock and makes it explicit. −Woodstone (talk) 07:36, 2 July 2019 (UTC)

I just don't understand what the phrase means in the context of the table. Jc3s5h (talk) 11:48, 2 July 2019 (UTC)

The table indicates how the 12-hour clock expresses instants in time. One of them is midnight at the end of a day (such as in the expiry of a contract). How would one make sure that midnight at the end of a specific day is meant? Saying just "midnight", although orally used, is ambiguous in writing. This midnight has to be expressed as the beginning of the next day. −Woodstone (talk) 14:49, 2 July 2019 (UTC)

This is a completely wrong-headed approach. The term "midnight", unless accompanied by a clarifying phrase such as "at the end of the day" is inherently ambiguous. The ambiguity can be resolved by context, or by custom in a particular field. For example, most US newspapers follow the AP Stylebook which specifies that midnight belongs to the day that is ending, so US newspaper readers might get used to this idea in the context of a newspaper (or they might not, so the smart editor won't count on readers understanding this convention).

It is not the purpose of the table to tell readers how to write "midnight" and surrounding words, it is to give a list of what happens. Midnight, in actual occurrence in writing, may belong to the day that is ending, the day that is beginning, or be an instant in time that separates the two days but belongs to neither.

Any statement in Wikipedia's voice equivalent to your "This midnight has to be expressed as the beginning of the next day" is unacceptable. It agrees with some of the reliable sources and disagrees with others. Since high-quality sources disagree, Wikipedia cannot take a position one way or the other. Jc3s5h (talk) 15:02, 2 July 2019 (UTC)

The last box in the table states precisely what you indicate here. Midnight as an instant in time can be viewed as begin or end of a day. That makes a difference when also a day is given or implied. The table gives alternatives for the way to write logical instants within a day and therefore has separate rows for each midnight bounding the day. The last point of the day can be written as "midnight" (with an implied "end of day"), or as the the beginning of the next day (12 a.m. with the next date). It gives alternatives and does not bias. −Woodstone (talk) 06:28, 3 July 2019 (UTC)

The table already has a pointer to "Confusion at noon and midnight" which explains this. It is confusing to have a notation in the last line of the table but not the first. Perhaps the first line should have a notation "see also last line of table" and the notation in the last line should be changed to "see also first line of table". But if one line has a notation, the other line should have a reciprocal notation. Jc3s5h (talk) 11:47, 3 July 2019 (UTC)

Table in noon and midnight section has incorrect entries

The NIST line is wrong. 12:01 am is 12:01 am. How else can you distinguish 12:01 am from 12:00 am? If it were 12:01 am and someone asked you the time, you would say 12:01 am. But 12:01 am is midnight according to the table. So when someone says it's 12:01 am, is it 12:01 am or midnight? This is ridiculous.

You use 12:01 am and 11:59 pm only when down-to-the-minute accuracy is not needed. While NIST doesn't explicitly say this, it is strongly implied (use in contracts is mentioned) and the only sensible interpretation. The table should reflect this.

It's nice to see the U.S. gov't finally got it right! (^_^)

Also, how about an entry for computers? It's not just digital watches. In fact, it's not just computers. It's digital displays in general.

Betaneptune (talk) 19:40, 19 November 2019 (UTC)

Are there any objections to changing "digital watches" to "digital displays" or "clocks with digital displays" or "digital clocks"? The first one is really too specific. Betaneptune (talk) 20:54, 20 October 2020 (UTC)

I don't mind changing "digital watches" to "clocks with digital displays" but you should start a new section rather than sticking this in the middle of a stale thread. Jc3s5h (talk) 22:36, 20 October 2020 (UTC)

Yes, it could be clearer. The intention, of course, is that 11:59 p.m. lasts up to 11:59.99; there is no midnight (the contract time changes at the instant of midnight from 11:59 to 12:01 a.m.); and 12:01 starts at 12:00.01

How can we express this more clearly? This is for contexts where the date is more important than the time to the exact second. Dbfirs 21:08, 19 November 2019 (UTC)

My only concern is that the table possibly gives the mistaken impression that 12:01 AM and 11:59 PM are midnight and noon, respectively. Perhaps I'm going too much by how the article was years ago, the last time I took an active part in it, when it was a disaster. My impression here is that 12:01 AM and 11:59 PM are being used as close enough to midnight and noon for most purposes, but still different, so as to make clear what day is meant. But the article and/or table isn't making that clear. So why not just state that? That is clearly the intent of the NIST bit. --Betaneptune (talk) 21:49, 19 November 2019 (UTC)

Noon isn't involved here. The explanation is in the adjoining text. Dbfirs 21:59, 19 November 2019 (UTC)

Right. Sorry. Strike noon. Should be beginning of day instead. Thanks. (^_^) Betaneptune (talk) 22:43, 19 November 2019 (UTC)

"Japanese legal convention [dubious]"

The linked source didn't mention it being legally required or enforced (in fact, most digital watches follow the 11AM–12PM convention), but as someone who spent their childhood in Japan, I can tell you where it is used: television. Anchors on networks like NHK would always announce the time as 0 PM at noon, which means they use 0-indexed 12-hour notation. The linked source also mentioned that the 0-indexed 12-hour notation is taught at schools. 202.144.171.174 (talk) 16:31, 21 June 2020 (UTC)

What is the actual problem with it? The word legal in Japanese legal convention doesn't mean it's required to be used in digital watches or wherever but just that it's the convention used in Japanese legalese. One can find it used in the text of the law and in documents like vehicle insurance (per source). Here's the same thing put another way: [1]. As the source and comment above show, the convention used in TV, radio, etc that uses 0 PM for noon follows "how it's taught in school" and is actually a logical extension of the legal one that uses 0 AM (午前0時) for midnight but 12 AM (午前12時) for noon (although at least one regulation exists that used 午後零時, i.e. 0 PM; see ja:午前と午後#午前・午後の根拠). Both calling it Japanese legal convention and actual values shown in table in the current revision of the article seem accurate to me.

The editor who added the template in Special:Diff/688937507 said in the edit summary that dubious Japanese legal convention makes no mention of "AM/PM" and didn't discuss it any further. If the problem is that the linked source and Japanese in general don't use the abbreviations AM/PM then it's technically correct and it probably should use 午前0時, 午前12時, and 午後12時 in the table to be truthful to typographic conventions, but 午前 and 午後 are considered equivalent to English AM and PM so I'm not sure if that would be any improvement in the context of noon/midnight distinction.

I can't see any other fault in either the source or the way it was used here. Does anyone object just removing that template? –MwGamera (talk) 06:22, 15 August 2021 (UTC)

12 AM is noon and always has been

12 AM has never been midnight, and it doesn't logically make sense for it to be so why are 12 AM and 12 PM swapped 2601:242:4100:F200:418B:F12F:5C3:F4C0 (talk) 00:38, 24 February 2021 (UTC)

Every Wikipedia editor is unreliable. All contentious statements made in Wikipedia must obey the verifiability policy. A reliable source, the 2008 edition of the US Government Printing Office Style Manual is cited in the article and says that 12 AM is midnight of the day that is beginning. The 2016 edition says the same thing on page 275 (which is page 289 of the PDF). Since there is a significant source that says 12 a.m. is midnight, your assertion "12 AM has never been midnight" is just wrong. Jc3s5h (talk) 00:50, 24 February 2021 (UTC)

You are wrong about 12.00am and 12.00pm. The thing is that 12.00am comes directly after 11.59am and is am all the way through until it becomes 1.00pm - 12.00am - 12 midday - until the afternoon - 1 in the afternoon. Likewise, 12.00pm is 12 o'clock midnight and the time only becomes am (morning) when it becomes 1 in the morning - 1.00am. People have always got this wrong and I am surprised that Wikipedia is also making the same mistake.

Many thanks, Dave Rattle (dave.rattle@gmail.com) — Preceding unsigned comment added by 102.65.62.161 (talk) 07:37, 28 May 2021 (UTC)

Please have a look at any digital clock at any time between noon and 1 pm. What does the am/pm marker say? Case closed. −Woodstone (talk) 12:38, 31 May 2021 (UTC)

Does "Informal speech and rounding off" belong here?

it is useful, but most of the examples are not specific to 12 hour clock per se, could apply to 24hr time as well, I thinkFeldercarb (talk) 15:55, 8 June 2021 (UTC)