Examine individual changes
Appearance
This page allows you to examine the variables generated by the Edit Filter for an individual change.
Variables generated for this change
Variable | Value |
---|---|
Edit count of the user (user_editcount ) | 456 |
Name of the user account (user_name ) | 'Marlarkey' |
Type of the user account (user_type ) | 'named' |
Age of the user account (user_age ) | 466327528 |
Groups (including implicit) the user is in (user_groups ) | [
0 => '*',
1 => 'user',
2 => 'autoconfirmed'
] |
Rights that the user has (user_rights ) | [
0 => 'createaccount',
1 => 'read',
2 => 'edit',
3 => 'createtalk',
4 => 'viewmyprivateinfo',
5 => 'editmyprivateinfo',
6 => 'editmyoptions',
7 => 'abusefilter-log-detail',
8 => 'urlshortener-create-url',
9 => 'centralauth-merge',
10 => 'abusefilter-view',
11 => 'abusefilter-log',
12 => 'vipsscaler-test',
13 => 'collectionsaveasuserpage',
14 => 'reupload-own',
15 => 'move-rootuserpages',
16 => 'createpage',
17 => 'minoredit',
18 => 'editmyusercss',
19 => 'editmyuserjson',
20 => 'editmyuserjs',
21 => 'sendemail',
22 => 'applychangetags',
23 => 'viewmywatchlist',
24 => 'editmywatchlist',
25 => 'spamblacklistlog',
26 => 'mwoauthmanagemygrants',
27 => 'reupload',
28 => 'upload',
29 => 'move',
30 => 'autoconfirmed',
31 => 'editsemiprotected',
32 => 'skipcaptcha',
33 => 'ipinfo',
34 => 'ipinfo-view-basic',
35 => 'transcode-reset',
36 => 'transcode-status',
37 => 'createpagemainns',
38 => 'movestable',
39 => 'autoreview'
] |
Whether or not a user is editing through the mobile interface (user_mobile ) | false |
Whether the user is editing from mobile app (user_app ) | false |
Page ID (page_id ) | 241267 |
Page namespace (page_namespace ) | 0 |
Page title without namespace (page_title ) | '12-hour clock' |
Full page title (page_prefixedtitle ) | '12-hour clock' |
Edit protection level of the page (page_restrictions_edit ) | [] |
Page age in seconds (page_age ) | 673602170 |
Action (action ) | 'edit' |
Edit summary/reason (summary ) | '/* Confusion at noon and midnight */ Added clarity ~~~~' |
Time since last page edit in seconds (page_last_edit_age ) | 466622 |
Old content model (old_content_model ) | 'wikitext' |
New content model (new_content_model ) | 'wikitext' |
Old page wikitext, before the edit (old_wikitext ) | '{{Short description|Time counting system}}
{{Redirect|AM and PM|other uses|AM PM (disambiguation)}}
{{Redirect|Ante meridiem|text=For the meridian 180° both east and west of the prime meridian in a geographical coordinate system, see [[180th meridian|antimeridian]]}}
{{Use American English|date=January 2021}}
{{Use dmy dates|date=November 2017}}
The '''12-hour clock''' is a time convention in which the 24 hours of the day are divided into two periods: '''a.m.''' (from [[Latin]] '''{{Lang-la|ante meridiem|label=none}}''', translating to "before midday") and '''p.m.''' (from Latin '''{{Lang-la|post meridiem|label=none}}''', translating to "after midday").<ref name="EncyclopaediaBritannica">{{cite encyclopedia | title =Time | encyclopedia =The New Encyclopædia Britannica | volume =28 | pages =660 2a | year= 1986 }}<br />{{cite encyclopedia | title =Time | encyclopedia = Encyclopædia Britannica. Encyclopædia Britannica Online Library Edition | url = http://library.eb.com.au/eb/article-61027| access-date = 20 November 2013 |quote=The use of AM or PM to designate either noon or midnight can cause ambiguity.}} {{subscription required}} For different opinions on representation of midday and midnight, see [[#Confusion at noon and midnight]]</ref><ref name=NISTFAQ/> Each period consists of 12 hours numbered: 12 (acting as 0),<ref>{{Cite web |url=http://www.math.csusb.edu/faculty/susan/number_bracelets/mod_arith.html |title=Modular Arithmetic |date=25 August 2016 |access-date=28 November 2008 |first=Susan |last=Addington |archive-url=https://web.archive.org/web/20080704121745/http://www.math.csusb.edu/faculty/susan/number_bracelets/mod_arith.html |archive-date=4 July 2008 |url-status=dead }}</ref> 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, and 11. The 12-hour clock has been developed since the [[second millennium BC]] and reached its modern form in the 16th century.
The 12-hour time convention is common in several English-speaking nations and former British [[Crown colony|colonies]], as well as a few other countries. There is [[#Confusion at noon and midnight|no widely accepted convention]] for how [[Noon|midday]] and [[midnight]] should be represented: in English-speaking countries, "12 p.m." indicates 12 o'clock noon, while "12 a.m." means 12 o'clock midnight.<ref>{{Cite web |title=Is noon 12 am or 12 pm? |url=https://www.rmg.co.uk/stories/topics/noon-12-am-or-12-pm |access-date=2023-01-26 |website=Royal Museums Greenwich |language=en}}</ref><ref>{{Cite web |title=U.S. Government Printing Office Style Manual - Chapter 12 - Numerals |url=https://www.govinfo.gov/content/pkg/GPO-STYLEMANUAL-2008/html/GPO-STYLEMANUAL-2008-14.htm |access-date=2023-01-27 |website=govinfo.gov}}</ref><ref>{{Cite web |date=2020-10-22 |title=time of day, elapsed time |url=https://www.noslangues-ourlanguages.gc.ca/en/writing-tips-plus/time-of-day-elapsed-time |access-date=2023-01-27 |website=Resources of the Language Portal of Canada}}</ref>
{| align="right" class="wikitable" style="margin: 0 0 2em 2em; font-size: 95%"
|+ Clock system
|-
!12-hour||[[24-hour clock|24-hour]]
|-
|Midnight <small>(start of day)</small><br>12 midnight<br>12:00 a.m.{{efn|name=noonmidnight|See: [[#Confusion at noon and midnight|§Confusion<br>at noon and midnight]]}}||00:00
|-
|12:01 a.m.||00:01
|-
|{{figure space}}1:00 a.m.||01:00
|-
|11:00 a.m.||11:00
|-
|11:59 a.m.||11:59
|-
|Noon<br>12 noon<br>12:00 p.m.{{efn|name=noonmidnight}}||12:00
|-
|12:01 p.m.||12:01
|-
|{{figure space}}1:00 p.m.||13:00
|-
|11:00 p.m.||23:00
|-
|11:59 p.m.||23:59
|-
|Midnight <small>(end of day)<br>''or shown as start of next day''</small>{{efn|name=noonmidnight}}||24:00
(00:00)
|-
|colspan="2"| {{notelist}}
|}
==History and use==
[[File:Exeter Cathedral astronomical clock.jpg|thumb|upright|[[Exeter Cathedral Astronomical Clock]], showing the double-XII numbering scheme.]]
The natural day-and-night division of a calendar day forms the fundamental basis as to why each day is split into two cycles. Originally there were two cycles: one cycle which could be tracked by the position of the Sun (day), followed by one cycle which could be tracked by the Moon and stars (night). This eventually evolved into the two 12-hour periods which are used today, one called "a.m." starting at midnight and another called "p.m." starting at noon. Noon itself is rarely abbreviated today; but if it is, it is denoted "m."<ref name=EncyclopaediaBritannica/>
The 12-hour clock can be traced back as far as [[Mesopotamia]] and [[ancient Egypt]].<ref>{{Cite web|url=http://www.arcytech.org/java/clock/clock_history.html|archive-url=https://web.archive.org/web/20081013135550/http://www.arcytech.org/java/clock/clock_history.html|url-status=dead|archive-date=13 October 2008|title=The History of Clocks|date=13 October 2008|access-date=12 November 2017}}</ref> Both an Egyptian [[sundial]] for daytime use<ref>{{cite web|url=http://members.aon.at/sundials/berlin-egypte.htm|title=Berlin instruments of the old Eg.time of day destination|website=members.aon.at|access-date=13 June 2006|archive-url=https://web.archive.org/web/20061115233642/http://members.aon.at/sundials/berlin-egypte.htm|archive-date=15 November 2006|url-status=live}}</ref> and an Egyptian [[water clock]] for night-time use were found in the tomb of Pharaoh [[Amenhotep I]].<ref>{{cite web|url=https://www.nist.gov/pml/time-and-frequency-division/popular-links/walk-through-time/walk-through-time-early-clocks|work=A Walk Through Time|title=Early Clocks|date=12 August 2009 |publisher=[[National Institute of Standards and Technology]]}}</ref> Dating to {{Circa|1500 BC}}, these clocks divided their respective times of use into 12 hours each.
The [[ancient Rome|Romans]] also [[Roman timekeeping|used a 12-hour clock]]: daylight was divided into 12 equal hours (thus hours having varying length throughout the year) and the night was divided into four watches.{{citation needed|date=January 2023}}
The first mechanical clocks in the 14th century, if they had dials at all, showed all 24 hours using the [[24-hour analog dial]], influenced by astronomers' familiarity with the [[astrolabe]] and sundial and by their desire to model the [[Earth's rotation|Earth's apparent motion around the Sun]]. In [[Northern Europe]] these dials generally used the 12-hour [[numbering scheme]] in [[Roman numerals]] but showed both ''a.m.'' and ''p.m.'' periods in sequence. This is known as the double-XII system and can be seen on many surviving clock faces, such as those at [[Wells Cathedral clock|Wells]] and [[Exeter Cathedral#Clock|Exeter]].
Elsewhere in Europe, numbering was more likely to be based on the 24-hour system (I to XXIV). The 12-hour clock was used throughout the British empire.
During the 15th and 16th centuries, the 12-hour analog dial and time system gradually became established as standard throughout Northern Europe for general public use. The 24-hour analog dial was reserved for more specialized applications, such as [[astronomical clock]]s and chronometers.
Most analog clocks and watches today use the 12-hour dial, on which the shorter hour hand rotates once every 12 hours and twice in one day. Some analog clock dials have an inner ring of numbers along with the standard 1-to-12 numbered ring. The number 12 is paired either with a 00 or a 24, while the numbers 1 through 11 are paired with the numbers 13 through 23, respectively. This modification allows the clock to also be read in [[24-hour notation]]. This kind of 12-hour clock can be found in countries where the 24-hour clock is preferred.
===Use by country===
{{Main|Date and time representation by country}}
[[File:Westclox Big Ben.jpg|thumb|right|Typical [[Clock#Analog|analogue 12-hour clock]]]]
[[File:12 24 Hours World Map.svg|thumb|World map showing the usage of 12 or 24-hour clock in different countries{{legend|#f0027f|24-hour}}{{legend|#990052|24-hour (12-hour orally)}}{{legend|#7fc97f|Both in common use}}{{legend|#386cb0|12-hour}}]]
In several countries the 12-hour clock is the dominant written and spoken system of time, predominantly in nations that were part of the former British Empire, for example, the [[United Kingdom]], [[Republic of Ireland]], the [[United States]], [[Canada]] ([[Date and time notation in Canada#Time notation in French|excluding Quebec]]), [[Australia]], [[New Zealand]], [[South Africa]], [[India]], [[Pakistan]], and [[Bangladesh]], and others follow this convention as well, such as [[Mexico]] and the former American colony of the [[Philippines]]. Even in those countries where the 12-hour clock is predominant, there are frequently contexts (such as science, medicine, the military or transport) in which the 24-hour clock is preferred. In most countries, however, the [[24-hour clock]] is the standard system used, especially in writing. Some nations in Europe and Latin America use a combination of the two, preferring the 12-hour system in colloquial speech but using the 24-hour system in written form and in formal contexts.
The 12-hour clock in speech often uses phrases such as'' ... in the morning'','' ... in the afternoon'','' ... in the evening'', and ''... at night''. ''Rider's British Merlin'' almanac for 1795 and a similar almanac for 1773 published in London used them.<ref>{{cite book|url=http://catalogue.nla.gov.au/Record/4881611|title=National Library of Australia catalogue entry for ''Rider's British merlin: for the year of Our Lord God 1795''|year=1795 |publisher=Printed for the Company of Stationers, and sold by R. Horsfield, at Stationers-hall, near Ludgate-street |archive-url=https://web.archive.org/web/20130522172644/http://catalogue.nla.gov.au/Record/4881611|archive-date=22 May 2013|url-status=live}}</ref> Other than in English-speaking countries and some Spanish-speaking countries, the terms ''a.m.'' and ''p.m.'' are seldom used and often unknown.
===Computer support===
In most countries, computers by default show the time in 24-hour notation. Most operating systems, including [[Microsoft Windows]] and [[Unix-like]] systems such as [[Linux]] and [[macOS]], activate the 12-hour notation by default for a limited number of language and region settings. This behaviour can be changed by the user, such as with the [[Microsoft Windows|Windows]] operating system's "Region and Language" settings.<ref>{{cite web|url=http://www.bleepingcomputer.com/tutorials/customize-how-time-is-displayed-in-windows/|title=How to customize how the time is displayed in Windows|author=Lawrence Abrams|date=13 December 2012|access-date=26 October 2013|publisher=Bleeping Computer|archive-url=https://web.archive.org/web/20131029183705/http://www.bleepingcomputer.com/tutorials/customize-how-time-is-displayed-in-windows/|archive-date=29 October 2013|url-status=live}}</ref>
==Abbreviations==
[[File:Digital-clock-alarm.jpg|thumb|Typical [[digital clock|digital]] 12-hour alarm clock indicating ''p.m.'' with a dot to the left of the hour.]]The [[Latin]] abbreviations ''a.m.'' and ''p.m.'' (often written "am" and "pm", "AM" and "PM", or "A.M." and "P.M.") are used in [[English language|English]] and [[Spanish language|Spanish]].<ref>{{cite dictionary|dictionary=Diccionario panhispánico de dudas|url=http://buscon.rae.es/dpdI/SrvltGUIBusDPD?lema=hora2|title=hora|archive-url=https://web.archive.org/web/20110720024649/http://buscon.rae.es/dpdI/SrvltGUIBusDPD?lema=hora2|archive-date=20 July 2011|url-status=live|language=Spanish}}</ref> The equivalents in [[Greek language|Greek]] are {{lang|el|π.μ.}} and {{lang|el|μ.μ.}}, respectively, and in [[Sinhala language|Sinhala]] {{lang|si|පෙ.ව.}} ({{transliteration|si|''pe.va.''}}) for {{lang|si|පෙරවරු}} ({{transliteration|si|''peravaru''}}, {{lang|si|පෙර}} {{transliteration|si|''pera''}} – fore, pre) and {{lang|si|ප.ව.}} ({{transliteration|si|''pa.va.''}}) for {{lang|si|පස්වරු}} ({{transliteration|si|''pasvaru''}}, {{lang|si|පස්සේ}} {{transliteration|si|''passē''}} – after, post). However, noon is rarely abbreviated in either of these languages, noon normally being written in full. In Portuguese, there are two official options and many others used, for example, using 21:45, 21h45 or 21h45min (official ones) or 21:45 or 9:45 p.m. In [[Irish language|Irish]], ''a.m.'' and ''i.n.'' are used, standing for ''ar maidin'' ("in the morning") and ''iarnóin'' ("afternoon") respectively.
Most other languages lack formal abbreviations for "before noon" and "after noon", and their users use the 12-hour clock only orally and informally.{{Citation needed|date=December 2007}} However, in many languages, such as Russian and Hebrew, informal designations are used, such as "9 in the morning" or "3 in the night".
When abbreviations and phrases are omitted, one may rely on sentence context and societal norms to reduce ambiguity. For example, if one commutes to work at "9:00", 9:00 a.m. may be implied, but if a [[social dance]] is scheduled to begin at "9:00", it may begin at 9:00 p.m.
==Related conventions==
===Typography===
The terms "a.m." and "p.m." are abbreviations of the Latin {{Lang|la|ante meridiem}} (before midday) and {{Lang|la|post meridiem}} (after midday). Depending on the [[style guide]] referenced, the abbreviations "a.m." and "p.m." are variously written in [[small capital]]s ("{{smallcaps|am}}" and "{{smallcaps|pm}}"),{{citation needed|date=October 2021}} [[Letter case|uppercase]] letters without a [[full stop|period]] ("AM" and "PM"), uppercase letters with periods, or lowercase letters ("am" and "pm" or,<ref name=ESG /> "a.m." and "p.m.").{{citation needed|date=October 2021}} With the advent of computer generated and printed schedules, especially airlines, advertising, and television promotions, the "M" character is often omitted as providing no additional information as in "9:30A" or "10:00P".<ref>{{cite web |last=Watson |first=James Robert |title=A more efficient way to denote am or pm |url=https://www.jamesrobertwatson.com/ampm.html |website=Jim Watson professor of design |access-date=August 30, 2022}}</ref>
Some style guides suggest the use of a space between the number and the a.m. or p.m. abbreviation.{{citation needed|date=March 2011}} Style guides recommend not using a.m. and p.m. without a time preceding it.<ref>Hacker, Diana, A Writer's Reference, six edition, Bedford, St Martin's, Boston, 2007, section M4-c, p.308.</ref>
The hour/minute separator [[Date and time representation by country|varies between countries]]: some use a colon, others use a period (full stop),<ref name=ESG>{{cite book |title=Economist Style Guide |page=185 |edition=12th |isbn=9781781258316 |publisher=[[The Economist]] |date=2018}}</ref> and still others use the letter h.{{citation needed|date=October 2021}}<!-- Dubious. I have seen the h notation many times but only ever with 24-hour clock. --> (In some usages, particularly "[[military time]]", of the [[24-hour clock]], there is no separator between hours and minutes.<ref>{{cite book |author=<!--Staff writer(s); no by-line.--> |date=May 27, 2015 |title=The Tongue and Quill |publisher=US Air Force |url=https://static.e-publishing.af.mil/production/1/saf_cn/publication/afh33-337/afh33-337.pdf |page=356 |access-date=26 October 2021 |archive-date=26 November 2020 |archive-url=https://web.archive.org/web/20201126183321/https://static.e-publishing.af.mil/production/1/saf_cn/publication/afh33-337/afh33-337.pdf |url-status=dead }} Air Force Handbook 33-337.</ref> This style is not generally seen when the 12-hour clock is used.)
=== Encoding ===
Unicode specifies codepoints for "a.m." and "p.m." symbols, which are intended to be used only with [[CJK characters|Chinese-Japanese-Korean]] (CJK) character sets, as they take up exactly the same space as one CJK character:
* {{unichar
| 33C2
| SQUARE AM<!-- Unicode name -->
| ulink =
| image =
| size = 150%
| html =
}}
* {{unichar
| 33D8
| SQUARE PM<!-- Unicode name -->
| ulink =
| image =
| size = 150%
| html = }}
===Informal speech and rounding off===
In speaking, it is common to round the time to the nearest five minutes and/or express the time as the past (or to) the closest hour; for example, "five past five" (5:05). Minutes ''past'' the hour means those minutes are added to the hour; "ten past five" means 5:10. Minutes ''to, 'til'' and ''of'' the hour mean those minutes are subtracted; "ten of five", "ten 'til five", and "ten to five" all mean 4:50.
Fifteen minutes is often called a ''quarter hour'', and thirty minutes is often known as a ''half hour''. For example, 5:15 can be phrased "(a) quarter past five" or "five-fifteen"; 5:30 can be "half past five", "five-thirty" or simply "half five". The time 8:45 may be spoken as "eight forty-five" or "(a) quarter to nine".<ref>{{cite dictionary|title=quarter|dictionary=American Heritage Dictionary|edition=3rd|location=Boston|publisher=Houghton Mifflin|date=1992}} s.v. usage note at end of "quarter" entry.</ref>
In older English, it was common for the number 25 to be expressed as "five-and-twenty".<ref>{{cite book |last1=Dickens |first1=Charles |title=Little Dorrit |date=1855 |page=Chapter 27}}</ref> In this way the time 8:35 may be phrased as "five-and-twenty to 9",<ref>{{cite web |last1=Trudgill |first1=Peter |title=Number five-and-twenty: A fading linguistic practice |url=https://www.theneweuropean.co.uk/brexit-news-peter-trudgill-recounts-the-old-way-of-counting-80170/ |website=The New European |date=17 May 2020 |access-date=13 October 2022}}</ref> although this styling fell out of fashion in the later part of the 1900s and is now rarely used.<ref>{{cite web |last1=Swan |first1=Michael |title=Ask About English |url=https://www.bbc.co.uk/worldservice/learningenglish/radio/specials/1535_questionanswer/page63.shtml |website=BBC World Service |publisher=BBC |access-date=13 January 2021}}</ref>
Instead of meaning 5:30, the "half five" expression is sometimes used to mean 4:30, or "halfway to five", especially for regions such as the [[Midwestern United States|American Midwest]] and other areas that have been particularly [[German America|influenced by German culture]].{{cn|date=November 2023}} This meaning follows the pattern choices of many Germanic and [[Slavic languages]], including [[Serbo-Croatian]], [[Dutch language|Dutch]], [[Danish language|Danish]], [[Russian language|Russian]], and [[Swedish language|Swedish]], as well as [[Hungarian language|Hungarian]], [[Finnish language|Finnish]], and the languages of the [[Baltic states|Baltic States]].
Moreover, in situations where the relevant hour is obvious or has been recently mentioned, a speaker might omit the hour and just say "quarter to (the hour)", "half past" or "ten 'til" to avoid an elaborate sentence in informal conversations. These forms are often commonly used in television and radio broadcasts that cover multiple time zones at one-hour intervals.<ref>{{Cite magazine|magazine=TVTimes|date=21–27 May 1983|url=http://forums.doyouremember.co.uk/threads/8061-TVTimes-magazine-21-27-May-1983-part1 |archive-url=https://web.archive.org/web/20121018072904/http://forums.doyouremember.co.uk/threads/8061-TVTimes-magazine-21-27-May-1983-part1|archive-date=18 October 2012|url-status=live |title=TVTimes magazine 21-27 May 1983 part1 |access-date=8 October 2019}}</ref>
In describing a vague time of day, a speaker might say the phrase "seven-thirty, eight" to mean sometime around 7:30 or 8:00. Such phrasing can be misinterpreted for a specific time of day (here 7:38), especially by a listener not expecting an estimation. The phrase "''about'' seven-thirty ''or'' eight" clarifies this.
Some more ambiguous phrasing might be avoided. Within five minutes of the hour, the phrase "five of seven" (6:55) can be heard "five-oh-seven" (5:07). "Five ''to'' seven" or even "six fifty-five" clarifies this.
===Formal speech and times to the minute===
{{redirect|O'clock|the o'clock watch|O bag}}
{{Unreferenced section|date=October 2020}}
Minutes may be expressed as an exact number of minutes past the hour specifying the time of day (e.g., 6:32 p.m. is "six thirty-two"). Additionally, when expressing the time using the "past (after)" or "to (before)" formula, it is conventional to choose the number of minutes below 30 (e.g., 6:32 p.m. is conventionally "twenty-eight minutes to seven" rather than "thirty-two minutes past six").
In spoken English, full hours are often represented by the numbered hour followed by [[wikt:o'clock|''o'clock'']] (10:00 as ''ten o'clock'', 2:00 as ''two o'clock''). This may be followed by the "a.m." or "p.m." designator, though some phrases such as ''in the morning, in the afternoon, in the evening,'' or ''at night'' more commonly follow analog-style terms such as ''o'clock, half past three,'' and ''quarter to four. O'clock'' itself may be omitted, telling a time as ''four a.m.'' or ''four p.m.'' Minutes ":01" to ":09" are usually pronounced as ''oh one'' to ''oh nine'' (''nought'' or ''zero'' can also be used instead of ''oh''). Minutes ":10" to ":59" are pronounced as their usual number-words. For instance, 6:02 a.m. can be pronounced ''six oh two a.m.'' whereas 6:32 a.m. could be told as ''six thirty-two a.m.''.
==Confusion at noon and midnight==
{| align="right" class="wikitable" style="margin: 0 0 1em 1em; font-size: 95%; width: 35em"
|+ Time according to various conventions
|-
!Device or [[style guide|style]]||[[Midnight]]<br /><small>Start of day</small>||[[Noon]]||Midnight<br /><small>End of day</small>
|-
|Written 24-hour time ||00:00||12:00||24:00
|-
| Digital watches (12-hour) || 12:00 AM || 12:00 PM || 12:00 AM
|-
| Digital watches (24-hour) || 0:00 || 12:00 || 0:00
|-
|[[United States Government Publishing Office|U.S. Government Publishing Office]] (1953)<ref name="GPO1953">{{cite web |url=https://www.govinfo.gov/content/pkg/GOVPUB-GP-6eda8715b8f5cb1d8514325b97334d4f/pdf/GOVPUB-GP-6eda8715b8f5cb1d8514325b97334d4f.pdf |pages=152, 267 |title=United States Government Printing Office Style Manual |date=January 1953 |website=govinfo |publisher=U.S. Government Publishing Office |access-date=5 September 2019 |archive-url=https://web.archive.org/web/20190905161607/https://www.govinfo.gov/content/pkg/GOVPUB-GP-6eda8715b8f5cb1d8514325b97334d4f/pdf/GOVPUB-GP-6eda8715b8f5cb1d8514325b97334d4f.pdf |archive-date=5 September 2019 |url-status=live }}</ref>||midnight{{efn|name=startend|These styles are ambiguous with respect to whether midnight is at the start or end of each day.}}||noon<br />12 o'clock noon<br />12 m.||midnight{{efn|name=startend}}<br />12:00 p.m.
|-
|U.S. Government Publishing Office (2000)<ref name="GPO2000">{{cite web |url=https://www.govinfo.gov/content/pkg/GPO-STYLEMANUAL-2000/pdf/GPO-STYLEMANUAL-2000.pdf |title=U.S. Government Printing Office Style Manual |at=page 156 |website=govinfo |date=2000 |publisher=U.S. Government Publishing Office |access-date=5 September 2019 |archive-url=https://web.archive.org/web/20190905160112/https://www.govinfo.gov/content/pkg/GPO-STYLEMANUAL-2000/pdf/GPO-STYLEMANUAL-2000.pdf |archive-date=5 September 2019 |url-status=live }}</ref>||midnight{{efn|name=startend}}||12 a.m.<br />noon||12 p.m.<br />midnight{{efn|name=startend}}
|-
|U.S. Government Publishing Office (2008)<ref name="GPO2008">{{cite web|url=https://www.govinfo.gov/content/pkg/GPO-STYLEMANUAL-2008/pdf/GPO-STYLEMANUAL-2008.pdf|title=U.S. Government Printing Office Style Manual|page=271|website=govinfo|date=2008|publisher=U.S. Government Publishing Office|access-date=5 September 2019|archive-url=https://web.archive.org/web/20190412235057/https://www.govinfo.gov/content/pkg/GPO-STYLEMANUAL-2008/pdf/GPO-STYLEMANUAL-2008.pdf|archive-date=12 April 2019|url-status=live}}</ref>||12 a.m.<br />12 midnight{{efn|name=startend}}||12 p.m.<br />12 noon||12 midnight{{efn|name=startend}}
|-
|Japanese legal convention<ref>{{cite web |script-title=ja:午前12時? 午後0時? |trans-title=12 AM? or 0 PM? |url=http://jjy.nict.go.jp/QandA/FAQ/12am-or-0pm-J.html |date=15 February 1989 |website=[[National Institute of Information and Communications Technology]] |language=ja |access-date=24 May 2017 |archive-url=https://web.archive.org/web/20170606032129/http://jjy.nict.go.jp/QandA/FAQ/12am-or-0pm-J.html |archive-date=6 June 2017 |url-status=dead}}</ref>||{{lang|ja|午前0時}} (0 a.m.)
|{{lang|ja|午前12時}} (12 a.m.)
|{{lang|ja|午後12時}} (12 p.m.)
|-
|Japanese common usage<ref name=":0">{{cite news |script-title=ja:質問4-1)正午は午前12時?それとも、午後12時? |trans-title=Question 4-1) Is noon 12 a.m.? Or 12 p.m.? |url=https://www.nao.ac.jp/faq/a0401.html |website=[[National Astronomical Observatory of Japan ]] |language=ja |access-date=19 January 2022 }}</ref>||{{lang|ja|午前0時}} (0 a.m.)
|{{lang|ja|午後0時}} (0 p.m.)
|{{lang|ja|午後12時}} (12 p.m.)
|-
|Chicago Manual of Style<ref name="chicago">{{cite book|title = Chicago Manual of Style | at = paragraph 9.38 | edition = 17th | date = 2017 | publisher = University of Chicago Press | quote = Although noon can be expressed as 12:00 m. (m = ''meridies''), very few use that form. | isbn=978-0-226-28705-8}}</ref> || ||noon<br />12:00 m.||
|-
|[[Canadian Press]],<ref name="CP" /> UK standard<ref name="NPL" />||Midnight||Noon||Midnight
|-
|Associated Press style<ref name="AP">Paula Froke, Anna Joe Bratton, Oskar Garcia, Jeff McMillan & Jerry Schwart, Eds., 54th ed., ''The Associated Press Stylebook and Briefing on Media Law'', New York: Basic Books, June 2019, {{ISBN|978-1-5416-9989-2}}, s.v. noon, midnight, times.</ref>||—||noon||midnight
|-
|[[National Institute of Standards and Technology|NIST]]<ref name="NISTFAQ" />||midnight{{efn|name=niststartend|NIST recommends using 11:59 p.m. and 12:01 a.m. to disambiguate when needed.}}<br />12:01 a.m.||noon||midnight{{efn|name=niststartend}}<br />11:59 p.m.
|-
|colspan="4"|{{noteslist}}
|}
It is not always clear what times "12:00 a.m." and "12:00 p.m." denote. From the [[Latin]] words {{lang|la|meridies}} (midday), ''ante'' (before) and ''post'' (after), the term ''{{Lang|la|ante meridiem}}'' (a.m.) means before midday and ''{{Lang|la|post meridiem}}'' (p.m.) means after midday. Since "noon" (midday, {{lang|la|meridies}} (m.)) is neither before nor after itself, the terms a.m. and p.m. do not apply.<ref name=NISTFAQ /> Although "12 m." was suggested as a way to indicate noon, this is seldom done<ref name="chicago" /> and also does not resolve the question of how to indicate midnight.
''[[The American Heritage Dictionary of the English Language]]'' states "By convention, ''12 AM'' denotes midnight and ''12 PM'' denotes noon. Because of the potential for confusion, it is advisable to use ''12 noon'' and ''12 midnight''".<ref>{{cite dictionary|url=http://ahdictionary.com/word/search.html?q=AM|title=AM|archive-url=https://web.archive.org/web/20140109230904/http://ahdictionary.com/word/search.html?q=AM|archive-date=9 January 2014|url-status=live|dictionary=[[The American Heritage Dictionary of the English Language]]|edition=Fifth|date=2011}}</ref>
E. G. Richards in his book ''Mapping Time'' (1999) provided a diagram in which 12 a.m. means noon and 12 p.m. means midnight.<ref>{{cite book|last=Richards|first=E. G.|title=Mapping Time: the Calendar and its History|publisher=[[Oxford University Press]]|date=1999|page=289}}</ref>
Historically, the style manual of the [[United States Government Printing Office]] used 12 a.m. for noon and 12 p.m. for midnight until its 2008 edition. At this point it reversed these designations<ref name="GPO2000" /><ref name="GPO2008" /> and then retained that change in its 2016 revision.<ref>{{cite web|url=https://www.govinfo.gov/features/new-edition-gpo-style-manual|title=GPO Style Manual. 2016. p.236|website=govinfo.gov| date=12 January 2017 |access-date=16 March 2018|archive-url=https://web.archive.org/web/20180317035857/https://www.govinfo.gov/features/new-edition-gpo-style-manual|archive-date=17 March 2018|url-status=live}}</ref>
Many U.S. style guides, and [[National Institute of Standards and Technology|NIST]]'s "Frequently asked questions (FAQ)" web page,<ref name=NISTFAQ>{{cite web|url=https://www.nist.gov/pml/time-and-frequency-division/times-day-faqs|title=Times of Day FAQs |publisher=[[National Institute of Standards and Technology]]|date=21 September 2016|access-date=30 September 2018|archive-url=https://web.archive.org/web/20180921153333/https://www.nist.gov/pml/time-and-frequency-division/times-day-faqs|archive-date=21 September 2018|url-status=live}}</ref> recommend that it is clearest if one refers to "noon" or "12:00 noon" and "midnight" or "12:00 midnight" (rather than to "12:00 p.m." and "12:00 a.m."). The NIST website states that "12 a.m. and 12 p.m. are ambiguous and should not be used."
''The Associated Press Stylebook'' specifies that midnight "is part of the day that is ending, not the one that is beginning."<ref name="AP" />
''The Canadian Press Stylebook''<ref name="CP">{{cite book|title=The Canadian Press Stylebook|edition= 11th |date = 1999 | at = page 288}}</ref> says, "write ''noon'' or ''midnight'', not ''12 noon'' or ''12 midnight''." Phrases such as "12 a.m." and "12 p.m." are not mentioned at all.
In the UK, the [[National Physical Laboratory (United Kingdom)|National Physical Laboratory]] "FAQ-Time" web page<ref name="NPL">{{Cite web |url=http://www.npl.co.uk/science-technology/time-frequency/time/faqs |title=National Physical Laboratory, ''FAQ-Time'' |access-date=11 January 2015 |archive-url=https://web.archive.org/web/20150303095129/http://www.npl.co.uk/science-technology/time-frequency/time/faqs/ |archive-date=3 March 2015 |url-status=dead }}</ref> states "In cases where the context cannot be relied upon to place a particular event, the pair of days straddling midnight can be quoted"; also "the terms 12 a.m. and 12 p.m. should be avoided."
Likewise, some U.S. style guides recommend either clarifying "midnight" with other context clues, such as specifying the two dates between which it falls, or not referring to the term at all. For an example of the latter method, "midnight" is replaced with "11:59 p.m." for the end of a day or "12:01 a.m." for the start of a day. That has become common in the United States in legal contracts and for [[airplane]], [[bus]], or [[train]] schedules, though some schedules use other conventions. Occasionally, when trains run at regular intervals, the pattern may be broken at midnight by displacing the midnight departure one or more minutes, such as to 11:59 p.m. or 12:01 a.m.<ref>{{cite web|url=http://www.abelliogreateranglia.co.uk/f/62130/62130.pdf|title=Cheshunt/Enfield Town to London Liverpool Street via Seven Sisters service Interim train timetables|archive-url=https://web.archive.org/web/20150526154117/http://www.abelliogreateranglia.co.uk/f/62130/62130.pdf|archive-date=26 May 2015|url-status=dead|website=Abellio Greater Anglia London|date=17 May 2015|pages=7,8}}</ref>
In [[Date and time notation in Japan|Japanese usage]], midnight is written as {{lang|ja|午前0時}} (0 a.m.) and noon is written as {{lang|ja|午後0時}} (0 p.m.), making the hours numbered sequentially from 0 to 11 in both halves of the day. Alternatively, noon may be written as {{lang|ja|午前12時}} (12 a.m.) and midnight at the end of the day as {{lang|ja|午後12時}} (12 p.m.), as opposed to {{lang|ja|午前0時}} (0 a.m.) for the start of the day, making the Japanese convention the opposite of the English usage of 12 a.m. and 12 p.m.<ref name=":0" />
==See also==
{{div col|colwidth=30em}}
* [[24-hour clock]]
* [[Clock position]]
* [[Date and time representation by country]]
* [[Decimal time]]
* [[Italian six-hour clock]]
* [[Midnight]]
* [[Muhurta]]
* [[Noon]]
* [[Pahar]]
* [[Thai six-hour clock]]
{{div col end}}
==References==
{{reflist|30em}}
==External links==
* [https://www.nist.gov/pml/div688/times.cfm NIST FAQ on time]
* [https://longtailworld.blogspot.com/2006/04/japan1212am-is-noon-in-japan.html 12am is noon in Japan]
{{Time Topics}}
{{Time measurement and standards}}
{{DEFAULTSORT:12-Hour Clock}}
[[Category:Date and time representation]]
[[Category:Time measurement systems]]' |
New page wikitext, after the edit (new_wikitext ) | '{{Short description|Time counting system}}
{{Redirect|AM and PM|other uses|AM PM (disambiguation)}}
{{Redirect|Ante meridiem|text=For the meridian 180° both east and west of the prime meridian in a geographical coordinate system, see [[180th meridian|antimeridian]]}}
{{Use American English|date=January 2021}}
{{Use dmy dates|date=November 2017}}
The '''12-hour clock''' is a time convention in which the 24 hours of the day are divided into two periods: '''a.m.''' (from [[Latin]] '''{{Lang-la|ante meridiem|label=none}}''', translating to "before midday") and '''p.m.''' (from Latin '''{{Lang-la|post meridiem|label=none}}''', translating to "after midday").<ref name="EncyclopaediaBritannica">{{cite encyclopedia | title =Time | encyclopedia =The New Encyclopædia Britannica | volume =28 | pages =660 2a | year= 1986 }}<br />{{cite encyclopedia | title =Time | encyclopedia = Encyclopædia Britannica. Encyclopædia Britannica Online Library Edition | url = http://library.eb.com.au/eb/article-61027| access-date = 20 November 2013 |quote=The use of AM or PM to designate either noon or midnight can cause ambiguity.}} {{subscription required}} For different opinions on representation of midday and midnight, see [[#Confusion at noon and midnight]]</ref><ref name=NISTFAQ/> Each period consists of 12 hours numbered: 12 (acting as 0),<ref>{{Cite web |url=http://www.math.csusb.edu/faculty/susan/number_bracelets/mod_arith.html |title=Modular Arithmetic |date=25 August 2016 |access-date=28 November 2008 |first=Susan |last=Addington |archive-url=https://web.archive.org/web/20080704121745/http://www.math.csusb.edu/faculty/susan/number_bracelets/mod_arith.html |archive-date=4 July 2008 |url-status=dead }}</ref> 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, and 11. The 12-hour clock has been developed since the [[second millennium BC]] and reached its modern form in the 16th century.
The 12-hour time convention is common in several English-speaking nations and former British [[Crown colony|colonies]], as well as a few other countries. There is [[#Confusion at noon and midnight|no widely accepted convention]] for how [[Noon|midday]] and [[midnight]] should be represented: in English-speaking countries, "12 p.m." indicates 12 o'clock noon, while "12 a.m." means 12 o'clock midnight.<ref>{{Cite web |title=Is noon 12 am or 12 pm? |url=https://www.rmg.co.uk/stories/topics/noon-12-am-or-12-pm |access-date=2023-01-26 |website=Royal Museums Greenwich |language=en}}</ref><ref>{{Cite web |title=U.S. Government Printing Office Style Manual - Chapter 12 - Numerals |url=https://www.govinfo.gov/content/pkg/GPO-STYLEMANUAL-2008/html/GPO-STYLEMANUAL-2008-14.htm |access-date=2023-01-27 |website=govinfo.gov}}</ref><ref>{{Cite web |date=2020-10-22 |title=time of day, elapsed time |url=https://www.noslangues-ourlanguages.gc.ca/en/writing-tips-plus/time-of-day-elapsed-time |access-date=2023-01-27 |website=Resources of the Language Portal of Canada}}</ref>
{| align="right" class="wikitable" style="margin: 0 0 2em 2em; font-size: 95%"
|+ Clock system
|-
!12-hour||[[24-hour clock|24-hour]]
|-
|Midnight <small>(start of day)</small><br>12 midnight<br>12:00 a.m.{{efn|name=noonmidnight|See: [[#Confusion at noon and midnight|§Confusion<br>at noon and midnight]]}}||00:00
|-
|12:01 a.m.||00:01
|-
|{{figure space}}1:00 a.m.||01:00
|-
|11:00 a.m.||11:00
|-
|11:59 a.m.||11:59
|-
|Noon<br>12 noon<br>12:00 p.m.{{efn|name=noonmidnight}}||12:00
|-
|12:01 p.m.||12:01
|-
|{{figure space}}1:00 p.m.||13:00
|-
|11:00 p.m.||23:00
|-
|11:59 p.m.||23:59
|-
|Midnight <small>(end of day)<br>''or shown as start of next day''</small>{{efn|name=noonmidnight}}||24:00
(00:00)
|-
|colspan="2"| {{notelist}}
|}
==History and use==
[[File:Exeter Cathedral astronomical clock.jpg|thumb|upright|[[Exeter Cathedral Astronomical Clock]], showing the double-XII numbering scheme.]]
The natural day-and-night division of a calendar day forms the fundamental basis as to why each day is split into two cycles. Originally there were two cycles: one cycle which could be tracked by the position of the Sun (day), followed by one cycle which could be tracked by the Moon and stars (night). This eventually evolved into the two 12-hour periods which are used today, one called "a.m." starting at midnight and another called "p.m." starting at noon. Noon itself is rarely abbreviated today; but if it is, it is denoted "m."<ref name=EncyclopaediaBritannica/>
The 12-hour clock can be traced back as far as [[Mesopotamia]] and [[ancient Egypt]].<ref>{{Cite web|url=http://www.arcytech.org/java/clock/clock_history.html|archive-url=https://web.archive.org/web/20081013135550/http://www.arcytech.org/java/clock/clock_history.html|url-status=dead|archive-date=13 October 2008|title=The History of Clocks|date=13 October 2008|access-date=12 November 2017}}</ref> Both an Egyptian [[sundial]] for daytime use<ref>{{cite web|url=http://members.aon.at/sundials/berlin-egypte.htm|title=Berlin instruments of the old Eg.time of day destination|website=members.aon.at|access-date=13 June 2006|archive-url=https://web.archive.org/web/20061115233642/http://members.aon.at/sundials/berlin-egypte.htm|archive-date=15 November 2006|url-status=live}}</ref> and an Egyptian [[water clock]] for night-time use were found in the tomb of Pharaoh [[Amenhotep I]].<ref>{{cite web|url=https://www.nist.gov/pml/time-and-frequency-division/popular-links/walk-through-time/walk-through-time-early-clocks|work=A Walk Through Time|title=Early Clocks|date=12 August 2009 |publisher=[[National Institute of Standards and Technology]]}}</ref> Dating to {{Circa|1500 BC}}, these clocks divided their respective times of use into 12 hours each.
The [[ancient Rome|Romans]] also [[Roman timekeeping|used a 12-hour clock]]: daylight was divided into 12 equal hours (thus hours having varying length throughout the year) and the night was divided into four watches.{{citation needed|date=January 2023}}
The first mechanical clocks in the 14th century, if they had dials at all, showed all 24 hours using the [[24-hour analog dial]], influenced by astronomers' familiarity with the [[astrolabe]] and sundial and by their desire to model the [[Earth's rotation|Earth's apparent motion around the Sun]]. In [[Northern Europe]] these dials generally used the 12-hour [[numbering scheme]] in [[Roman numerals]] but showed both ''a.m.'' and ''p.m.'' periods in sequence. This is known as the double-XII system and can be seen on many surviving clock faces, such as those at [[Wells Cathedral clock|Wells]] and [[Exeter Cathedral#Clock|Exeter]].
Elsewhere in Europe, numbering was more likely to be based on the 24-hour system (I to XXIV). The 12-hour clock was used throughout the British empire.
During the 15th and 16th centuries, the 12-hour analog dial and time system gradually became established as standard throughout Northern Europe for general public use. The 24-hour analog dial was reserved for more specialized applications, such as [[astronomical clock]]s and chronometers.
Most analog clocks and watches today use the 12-hour dial, on which the shorter hour hand rotates once every 12 hours and twice in one day. Some analog clock dials have an inner ring of numbers along with the standard 1-to-12 numbered ring. The number 12 is paired either with a 00 or a 24, while the numbers 1 through 11 are paired with the numbers 13 through 23, respectively. This modification allows the clock to also be read in [[24-hour notation]]. This kind of 12-hour clock can be found in countries where the 24-hour clock is preferred.
===Use by country===
{{Main|Date and time representation by country}}
[[File:Westclox Big Ben.jpg|thumb|right|Typical [[Clock#Analog|analogue 12-hour clock]]]]
[[File:12 24 Hours World Map.svg|thumb|World map showing the usage of 12 or 24-hour clock in different countries{{legend|#f0027f|24-hour}}{{legend|#990052|24-hour (12-hour orally)}}{{legend|#7fc97f|Both in common use}}{{legend|#386cb0|12-hour}}]]
In several countries the 12-hour clock is the dominant written and spoken system of time, predominantly in nations that were part of the former British Empire, for example, the [[United Kingdom]], [[Republic of Ireland]], the [[United States]], [[Canada]] ([[Date and time notation in Canada#Time notation in French|excluding Quebec]]), [[Australia]], [[New Zealand]], [[South Africa]], [[India]], [[Pakistan]], and [[Bangladesh]], and others follow this convention as well, such as [[Mexico]] and the former American colony of the [[Philippines]]. Even in those countries where the 12-hour clock is predominant, there are frequently contexts (such as science, medicine, the military or transport) in which the 24-hour clock is preferred. In most countries, however, the [[24-hour clock]] is the standard system used, especially in writing. Some nations in Europe and Latin America use a combination of the two, preferring the 12-hour system in colloquial speech but using the 24-hour system in written form and in formal contexts.
The 12-hour clock in speech often uses phrases such as'' ... in the morning'','' ... in the afternoon'','' ... in the evening'', and ''... at night''. ''Rider's British Merlin'' almanac for 1795 and a similar almanac for 1773 published in London used them.<ref>{{cite book|url=http://catalogue.nla.gov.au/Record/4881611|title=National Library of Australia catalogue entry for ''Rider's British merlin: for the year of Our Lord God 1795''|year=1795 |publisher=Printed for the Company of Stationers, and sold by R. Horsfield, at Stationers-hall, near Ludgate-street |archive-url=https://web.archive.org/web/20130522172644/http://catalogue.nla.gov.au/Record/4881611|archive-date=22 May 2013|url-status=live}}</ref> Other than in English-speaking countries and some Spanish-speaking countries, the terms ''a.m.'' and ''p.m.'' are seldom used and often unknown.
===Computer support===
In most countries, computers by default show the time in 24-hour notation. Most operating systems, including [[Microsoft Windows]] and [[Unix-like]] systems such as [[Linux]] and [[macOS]], activate the 12-hour notation by default for a limited number of language and region settings. This behaviour can be changed by the user, such as with the [[Microsoft Windows|Windows]] operating system's "Region and Language" settings.<ref>{{cite web|url=http://www.bleepingcomputer.com/tutorials/customize-how-time-is-displayed-in-windows/|title=How to customize how the time is displayed in Windows|author=Lawrence Abrams|date=13 December 2012|access-date=26 October 2013|publisher=Bleeping Computer|archive-url=https://web.archive.org/web/20131029183705/http://www.bleepingcomputer.com/tutorials/customize-how-time-is-displayed-in-windows/|archive-date=29 October 2013|url-status=live}}</ref>
==Abbreviations==
[[File:Digital-clock-alarm.jpg|thumb|Typical [[digital clock|digital]] 12-hour alarm clock indicating ''p.m.'' with a dot to the left of the hour.]]The [[Latin]] abbreviations ''a.m.'' and ''p.m.'' (often written "am" and "pm", "AM" and "PM", or "A.M." and "P.M.") are used in [[English language|English]] and [[Spanish language|Spanish]].<ref>{{cite dictionary|dictionary=Diccionario panhispánico de dudas|url=http://buscon.rae.es/dpdI/SrvltGUIBusDPD?lema=hora2|title=hora|archive-url=https://web.archive.org/web/20110720024649/http://buscon.rae.es/dpdI/SrvltGUIBusDPD?lema=hora2|archive-date=20 July 2011|url-status=live|language=Spanish}}</ref> The equivalents in [[Greek language|Greek]] are {{lang|el|π.μ.}} and {{lang|el|μ.μ.}}, respectively, and in [[Sinhala language|Sinhala]] {{lang|si|පෙ.ව.}} ({{transliteration|si|''pe.va.''}}) for {{lang|si|පෙරවරු}} ({{transliteration|si|''peravaru''}}, {{lang|si|පෙර}} {{transliteration|si|''pera''}} – fore, pre) and {{lang|si|ප.ව.}} ({{transliteration|si|''pa.va.''}}) for {{lang|si|පස්වරු}} ({{transliteration|si|''pasvaru''}}, {{lang|si|පස්සේ}} {{transliteration|si|''passē''}} – after, post). However, noon is rarely abbreviated in either of these languages, noon normally being written in full. In Portuguese, there are two official options and many others used, for example, using 21:45, 21h45 or 21h45min (official ones) or 21:45 or 9:45 p.m. In [[Irish language|Irish]], ''a.m.'' and ''i.n.'' are used, standing for ''ar maidin'' ("in the morning") and ''iarnóin'' ("afternoon") respectively.
Most other languages lack formal abbreviations for "before noon" and "after noon", and their users use the 12-hour clock only orally and informally.{{Citation needed|date=December 2007}} However, in many languages, such as Russian and Hebrew, informal designations are used, such as "9 in the morning" or "3 in the night".
When abbreviations and phrases are omitted, one may rely on sentence context and societal norms to reduce ambiguity. For example, if one commutes to work at "9:00", 9:00 a.m. may be implied, but if a [[social dance]] is scheduled to begin at "9:00", it may begin at 9:00 p.m.
==Related conventions==
===Typography===
The terms "a.m." and "p.m." are abbreviations of the Latin {{Lang|la|ante meridiem}} (before midday) and {{Lang|la|post meridiem}} (after midday). Depending on the [[style guide]] referenced, the abbreviations "a.m." and "p.m." are variously written in [[small capital]]s ("{{smallcaps|am}}" and "{{smallcaps|pm}}"),{{citation needed|date=October 2021}} [[Letter case|uppercase]] letters without a [[full stop|period]] ("AM" and "PM"), uppercase letters with periods, or lowercase letters ("am" and "pm" or,<ref name=ESG /> "a.m." and "p.m.").{{citation needed|date=October 2021}} With the advent of computer generated and printed schedules, especially airlines, advertising, and television promotions, the "M" character is often omitted as providing no additional information as in "9:30A" or "10:00P".<ref>{{cite web |last=Watson |first=James Robert |title=A more efficient way to denote am or pm |url=https://www.jamesrobertwatson.com/ampm.html |website=Jim Watson professor of design |access-date=August 30, 2022}}</ref>
Some style guides suggest the use of a space between the number and the a.m. or p.m. abbreviation.{{citation needed|date=March 2011}} Style guides recommend not using a.m. and p.m. without a time preceding it.<ref>Hacker, Diana, A Writer's Reference, six edition, Bedford, St Martin's, Boston, 2007, section M4-c, p.308.</ref>
The hour/minute separator [[Date and time representation by country|varies between countries]]: some use a colon, others use a period (full stop),<ref name=ESG>{{cite book |title=Economist Style Guide |page=185 |edition=12th |isbn=9781781258316 |publisher=[[The Economist]] |date=2018}}</ref> and still others use the letter h.{{citation needed|date=October 2021}}<!-- Dubious. I have seen the h notation many times but only ever with 24-hour clock. --> (In some usages, particularly "[[military time]]", of the [[24-hour clock]], there is no separator between hours and minutes.<ref>{{cite book |author=<!--Staff writer(s); no by-line.--> |date=May 27, 2015 |title=The Tongue and Quill |publisher=US Air Force |url=https://static.e-publishing.af.mil/production/1/saf_cn/publication/afh33-337/afh33-337.pdf |page=356 |access-date=26 October 2021 |archive-date=26 November 2020 |archive-url=https://web.archive.org/web/20201126183321/https://static.e-publishing.af.mil/production/1/saf_cn/publication/afh33-337/afh33-337.pdf |url-status=dead }} Air Force Handbook 33-337.</ref> This style is not generally seen when the 12-hour clock is used.)
=== Encoding ===
Unicode specifies codepoints for "a.m." and "p.m." symbols, which are intended to be used only with [[CJK characters|Chinese-Japanese-Korean]] (CJK) character sets, as they take up exactly the same space as one CJK character:
* {{unichar
| 33C2
| SQUARE AM<!-- Unicode name -->
| ulink =
| image =
| size = 150%
| html =
}}
* {{unichar
| 33D8
| SQUARE PM<!-- Unicode name -->
| ulink =
| image =
| size = 150%
| html = }}
===Informal speech and rounding off===
In speaking, it is common to round the time to the nearest five minutes and/or express the time as the past (or to) the closest hour; for example, "five past five" (5:05). Minutes ''past'' the hour means those minutes are added to the hour; "ten past five" means 5:10. Minutes ''to, 'til'' and ''of'' the hour mean those minutes are subtracted; "ten of five", "ten 'til five", and "ten to five" all mean 4:50.
Fifteen minutes is often called a ''quarter hour'', and thirty minutes is often known as a ''half hour''. For example, 5:15 can be phrased "(a) quarter past five" or "five-fifteen"; 5:30 can be "half past five", "five-thirty" or simply "half five". The time 8:45 may be spoken as "eight forty-five" or "(a) quarter to nine".<ref>{{cite dictionary|title=quarter|dictionary=American Heritage Dictionary|edition=3rd|location=Boston|publisher=Houghton Mifflin|date=1992}} s.v. usage note at end of "quarter" entry.</ref>
In older English, it was common for the number 25 to be expressed as "five-and-twenty".<ref>{{cite book |last1=Dickens |first1=Charles |title=Little Dorrit |date=1855 |page=Chapter 27}}</ref> In this way the time 8:35 may be phrased as "five-and-twenty to 9",<ref>{{cite web |last1=Trudgill |first1=Peter |title=Number five-and-twenty: A fading linguistic practice |url=https://www.theneweuropean.co.uk/brexit-news-peter-trudgill-recounts-the-old-way-of-counting-80170/ |website=The New European |date=17 May 2020 |access-date=13 October 2022}}</ref> although this styling fell out of fashion in the later part of the 1900s and is now rarely used.<ref>{{cite web |last1=Swan |first1=Michael |title=Ask About English |url=https://www.bbc.co.uk/worldservice/learningenglish/radio/specials/1535_questionanswer/page63.shtml |website=BBC World Service |publisher=BBC |access-date=13 January 2021}}</ref>
Instead of meaning 5:30, the "half five" expression is sometimes used to mean 4:30, or "halfway to five", especially for regions such as the [[Midwestern United States|American Midwest]] and other areas that have been particularly [[German America|influenced by German culture]].{{cn|date=November 2023}} This meaning follows the pattern choices of many Germanic and [[Slavic languages]], including [[Serbo-Croatian]], [[Dutch language|Dutch]], [[Danish language|Danish]], [[Russian language|Russian]], and [[Swedish language|Swedish]], as well as [[Hungarian language|Hungarian]], [[Finnish language|Finnish]], and the languages of the [[Baltic states|Baltic States]].
Moreover, in situations where the relevant hour is obvious or has been recently mentioned, a speaker might omit the hour and just say "quarter to (the hour)", "half past" or "ten 'til" to avoid an elaborate sentence in informal conversations. These forms are often commonly used in television and radio broadcasts that cover multiple time zones at one-hour intervals.<ref>{{Cite magazine|magazine=TVTimes|date=21–27 May 1983|url=http://forums.doyouremember.co.uk/threads/8061-TVTimes-magazine-21-27-May-1983-part1 |archive-url=https://web.archive.org/web/20121018072904/http://forums.doyouremember.co.uk/threads/8061-TVTimes-magazine-21-27-May-1983-part1|archive-date=18 October 2012|url-status=live |title=TVTimes magazine 21-27 May 1983 part1 |access-date=8 October 2019}}</ref>
In describing a vague time of day, a speaker might say the phrase "seven-thirty, eight" to mean sometime around 7:30 or 8:00. Such phrasing can be misinterpreted for a specific time of day (here 7:38), especially by a listener not expecting an estimation. The phrase "''about'' seven-thirty ''or'' eight" clarifies this.
Some more ambiguous phrasing might be avoided. Within five minutes of the hour, the phrase "five of seven" (6:55) can be heard "five-oh-seven" (5:07). "Five ''to'' seven" or even "six fifty-five" clarifies this.
===Formal speech and times to the minute===
{{redirect|O'clock|the o'clock watch|O bag}}
{{Unreferenced section|date=October 2020}}
Minutes may be expressed as an exact number of minutes past the hour specifying the time of day (e.g., 6:32 p.m. is "six thirty-two"). Additionally, when expressing the time using the "past (after)" or "to (before)" formula, it is conventional to choose the number of minutes below 30 (e.g., 6:32 p.m. is conventionally "twenty-eight minutes to seven" rather than "thirty-two minutes past six").
In spoken English, full hours are often represented by the numbered hour followed by [[wikt:o'clock|''o'clock'']] (10:00 as ''ten o'clock'', 2:00 as ''two o'clock''). This may be followed by the "a.m." or "p.m." designator, though some phrases such as ''in the morning, in the afternoon, in the evening,'' or ''at night'' more commonly follow analog-style terms such as ''o'clock, half past three,'' and ''quarter to four. O'clock'' itself may be omitted, telling a time as ''four a.m.'' or ''four p.m.'' Minutes ":01" to ":09" are usually pronounced as ''oh one'' to ''oh nine'' (''nought'' or ''zero'' can also be used instead of ''oh''). Minutes ":10" to ":59" are pronounced as their usual number-words. For instance, 6:02 a.m. can be pronounced ''six oh two a.m.'' whereas 6:32 a.m. could be told as ''six thirty-two a.m.''.
==Confusion at noon and midnight==
{| align="right" class="wikitable" style="margin: 0 0 1em 1em; font-size: 95%; width: 35em"
|+ Time according to various conventions
|-
!Device or [[style guide|style]]||[[Midnight]]<br /><small>Start of day</small>||[[Noon]]||Midnight<br /><small>End of day</small>
|-
|Written 24-hour time ||00:00||12:00||24:00
|-
| Digital watches (12-hour) || 12:00 AM || 12:00 PM || 12:00 AM
|-
| Digital watches (24-hour) || 0:00 || 12:00 || 0:00
|-
|[[United States Government Publishing Office|U.S. Government Publishing Office]] (1953)<ref name="GPO1953">{{cite web |url=https://www.govinfo.gov/content/pkg/GOVPUB-GP-6eda8715b8f5cb1d8514325b97334d4f/pdf/GOVPUB-GP-6eda8715b8f5cb1d8514325b97334d4f.pdf |pages=152, 267 |title=United States Government Printing Office Style Manual |date=January 1953 |website=govinfo |publisher=U.S. Government Publishing Office |access-date=5 September 2019 |archive-url=https://web.archive.org/web/20190905161607/https://www.govinfo.gov/content/pkg/GOVPUB-GP-6eda8715b8f5cb1d8514325b97334d4f/pdf/GOVPUB-GP-6eda8715b8f5cb1d8514325b97334d4f.pdf |archive-date=5 September 2019 |url-status=live }}</ref>||midnight{{efn|name=startend|These styles are ambiguous with respect to whether midnight is at the start or end of each day.}}||noon<br />12 o'clock noon<br />12 m.||midnight{{efn|name=startend}}<br />12:00 p.m.
|-
|U.S. Government Publishing Office (2000)<ref name="GPO2000">{{cite web |url=https://www.govinfo.gov/content/pkg/GPO-STYLEMANUAL-2000/pdf/GPO-STYLEMANUAL-2000.pdf |title=U.S. Government Printing Office Style Manual |at=page 156 |website=govinfo |date=2000 |publisher=U.S. Government Publishing Office |access-date=5 September 2019 |archive-url=https://web.archive.org/web/20190905160112/https://www.govinfo.gov/content/pkg/GPO-STYLEMANUAL-2000/pdf/GPO-STYLEMANUAL-2000.pdf |archive-date=5 September 2019 |url-status=live }}</ref>||midnight{{efn|name=startend}}||12 a.m.<br />noon||12 p.m.<br />midnight{{efn|name=startend}}
|-
|U.S. Government Publishing Office (2008)<ref name="GPO2008">{{cite web|url=https://www.govinfo.gov/content/pkg/GPO-STYLEMANUAL-2008/pdf/GPO-STYLEMANUAL-2008.pdf|title=U.S. Government Printing Office Style Manual|page=271|website=govinfo|date=2008|publisher=U.S. Government Publishing Office|access-date=5 September 2019|archive-url=https://web.archive.org/web/20190412235057/https://www.govinfo.gov/content/pkg/GPO-STYLEMANUAL-2008/pdf/GPO-STYLEMANUAL-2008.pdf|archive-date=12 April 2019|url-status=live}}</ref>||12 a.m.<br />12 midnight{{efn|name=startend}}||12 p.m.<br />12 noon||12 midnight{{efn|name=startend}}
|-
|Japanese legal convention<ref>{{cite web |script-title=ja:午前12時? 午後0時? |trans-title=12 AM? or 0 PM? |url=http://jjy.nict.go.jp/QandA/FAQ/12am-or-0pm-J.html |date=15 February 1989 |website=[[National Institute of Information and Communications Technology]] |language=ja |access-date=24 May 2017 |archive-url=https://web.archive.org/web/20170606032129/http://jjy.nict.go.jp/QandA/FAQ/12am-or-0pm-J.html |archive-date=6 June 2017 |url-status=dead}}</ref>||{{lang|ja|午前0時}} (0 a.m.)
|{{lang|ja|午前12時}} (12 a.m.)
|{{lang|ja|午後12時}} (12 p.m.)
|-
|Japanese common usage<ref name=":0">{{cite news |script-title=ja:質問4-1)正午は午前12時?それとも、午後12時? |trans-title=Question 4-1) Is noon 12 a.m.? Or 12 p.m.? |url=https://www.nao.ac.jp/faq/a0401.html |website=[[National Astronomical Observatory of Japan ]] |language=ja |access-date=19 January 2022 }}</ref>||{{lang|ja|午前0時}} (0 a.m.)
|{{lang|ja|午後0時}} (0 p.m.)
|{{lang|ja|午後12時}} (12 p.m.)
|-
|Chicago Manual of Style<ref name="chicago">{{cite book|title = Chicago Manual of Style | at = paragraph 9.38 | edition = 17th | date = 2017 | publisher = University of Chicago Press | quote = Although noon can be expressed as 12:00 m. (m = ''meridies''), very few use that form. | isbn=978-0-226-28705-8}}</ref> || ||noon<br />12:00 m.||
|-
|[[Canadian Press]],<ref name="CP" /> UK standard<ref name="NPL" />||Midnight||Noon||Midnight
|-
|Associated Press style<ref name="AP">Paula Froke, Anna Joe Bratton, Oskar Garcia, Jeff McMillan & Jerry Schwart, Eds., 54th ed., ''The Associated Press Stylebook and Briefing on Media Law'', New York: Basic Books, June 2019, {{ISBN|978-1-5416-9989-2}}, s.v. noon, midnight, times.</ref>||—||noon||midnight
|-
|[[National Institute of Standards and Technology|NIST]]<ref name="NISTFAQ" />||midnight{{efn|name=niststartend|NIST recommends using 11:59 p.m. and 12:01 a.m. to disambiguate when needed.}}<br />12:01 a.m.||noon||midnight{{efn|name=niststartend}}<br />11:59 p.m.
|-
|colspan="4"|{{noteslist}}
|}
It is not always clear what times "12:00 a.m." and "12:00 p.m." denote. From the [[Latin]] words {{lang|la|meridies}} (midday), ''ante'' (before) and ''post'' (after), the term ''{{Lang|la|ante meridiem}}'' (a.m.) means before midday and ''{{Lang|la|post meridiem}}'' (p.m.) means after midday. Since "noon" (midday, {{lang|la|meridies}} (m.)) is neither before nor after itself, the terms a.m. and p.m. do not apply.<ref name=NISTFAQ /> Although "12 m." was suggested as a way to indicate noon, this is seldom done<ref name="chicago" /> and also does not resolve the question of how to indicate midnight.
''[[The American Heritage Dictionary of the English Language]]'' states "By convention, ''12 AM'' denotes midnight and ''12 PM'' denotes noon. However this is nonsensical because phrases such as "by midnight on Friday" clearly imply that midnight is at the end of Friday and part of Friday, and therefore midnight is after midday ON FRIDAY, hence to call it "am" (before midday) would be nonsensical. Because of the potential for confusion, it is advisable to use ''12 noon'' and ''12 midnight''".<ref>{{cite dictionary|url=http://ahdictionary.com/word/search.html?q=AM|title=AM|archive-url=https://web.archive.org/web/20140109230904/http://ahdictionary.com/word/search.html?q=AM|archive-date=9 January 2014|url-status=live|dictionary=[[The American Heritage Dictionary of the English Language]]|edition=Fifth|date=2011}}</ref>
E. G. Richards in his book ''Mapping Time'' (1999) provided a diagram in which 12 a.m. means noon and 12 p.m. means midnight.<ref>{{cite book|last=Richards|first=E. G.|title=Mapping Time: the Calendar and its History|publisher=[[Oxford University Press]]|date=1999|page=289}}</ref> This usage aligns with the usage that "by midnight on Friday" means that midnight on Friday is part of Friday (not Saturday) and because it is after noon it is post meridiem ie pm.
Historically, the style manual of the [[United States Government Printing Office]] used 12 a.m. for noon and 12 p.m. for midnight until its 2008 edition. At this point it reversed these designations<ref name="GPO2000" /><ref name="GPO2008" /> and then retained that change in its 2016 revision.<ref>{{cite web|url=https://www.govinfo.gov/features/new-edition-gpo-style-manual|title=GPO Style Manual. 2016. p.236|website=govinfo.gov| date=12 January 2017 |access-date=16 March 2018|archive-url=https://web.archive.org/web/20180317035857/https://www.govinfo.gov/features/new-edition-gpo-style-manual|archive-date=17 March 2018|url-status=live}}</ref>
Many U.S. style guides, and [[National Institute of Standards and Technology|NIST]]'s "Frequently asked questions (FAQ)" web page,<ref name=NISTFAQ>{{cite web|url=https://www.nist.gov/pml/time-and-frequency-division/times-day-faqs|title=Times of Day FAQs |publisher=[[National Institute of Standards and Technology]]|date=21 September 2016|access-date=30 September 2018|archive-url=https://web.archive.org/web/20180921153333/https://www.nist.gov/pml/time-and-frequency-division/times-day-faqs|archive-date=21 September 2018|url-status=live}}</ref> recommend that it is clearest if one refers to "noon" or "12:00 noon" and "midnight" or "12:00 midnight" (rather than to "12:00 p.m." and "12:00 a.m."). The NIST website states that "12 a.m. and 12 p.m. are ambiguous and should not be used."
''The Associated Press Stylebook'' specifies that midnight "is part of the day that is ending, not the one that is beginning."<ref name="AP" />
''The Canadian Press Stylebook''<ref name="CP">{{cite book|title=The Canadian Press Stylebook|edition= 11th |date = 1999 | at = page 288}}</ref> says, "write ''noon'' or ''midnight'', not ''12 noon'' or ''12 midnight''." Phrases such as "12 a.m." and "12 p.m." are not mentioned at all.
In the UK, the [[National Physical Laboratory (United Kingdom)|National Physical Laboratory]] "FAQ-Time" web page<ref name="NPL">{{Cite web |url=http://www.npl.co.uk/science-technology/time-frequency/time/faqs |title=National Physical Laboratory, ''FAQ-Time'' |access-date=11 January 2015 |archive-url=https://web.archive.org/web/20150303095129/http://www.npl.co.uk/science-technology/time-frequency/time/faqs/ |archive-date=3 March 2015 |url-status=dead }}</ref> states "In cases where the context cannot be relied upon to place a particular event, the pair of days straddling midnight can be quoted"; also "the terms 12 a.m. and 12 p.m. should be avoided."
Likewise, some U.S. style guides recommend either clarifying "midnight" with other context clues, such as specifying the two dates between which it falls, or not referring to the term at all. For an example of the latter method, "midnight" is replaced with "11:59 p.m." for the end of a day or "12:01 a.m." for the start of a day. That has become common in the United States in legal contracts and for [[airplane]], [[bus]], or [[train]] schedules, though some schedules use other conventions. Occasionally, when trains run at regular intervals, the pattern may be broken at midnight by displacing the midnight departure one or more minutes, such as to 11:59 p.m. or 12:01 a.m.<ref>{{cite web|url=http://www.abelliogreateranglia.co.uk/f/62130/62130.pdf|title=Cheshunt/Enfield Town to London Liverpool Street via Seven Sisters service Interim train timetables|archive-url=https://web.archive.org/web/20150526154117/http://www.abelliogreateranglia.co.uk/f/62130/62130.pdf|archive-date=26 May 2015|url-status=dead|website=Abellio Greater Anglia London|date=17 May 2015|pages=7,8}}</ref>
In [[Date and time notation in Japan|Japanese usage]], midnight is written as {{lang|ja|午前0時}} (0 a.m.) and noon is written as {{lang|ja|午後0時}} (0 p.m.), making the hours numbered sequentially from 0 to 11 in both halves of the day. Alternatively, noon may be written as {{lang|ja|午前12時}} (12 a.m.) and midnight at the end of the day as {{lang|ja|午後12時}} (12 p.m.), as opposed to {{lang|ja|午前0時}} (0 a.m.) for the start of the day, making the Japanese convention the opposite of the English usage of 12 a.m. and 12 p.m.<ref name=":0" />
==See also==
{{div col|colwidth=30em}}
* [[24-hour clock]]
* [[Clock position]]
* [[Date and time representation by country]]
* [[Decimal time]]
* [[Italian six-hour clock]]
* [[Midnight]]
* [[Muhurta]]
* [[Noon]]
* [[Pahar]]
* [[Thai six-hour clock]]
{{div col end}}
==References==
{{reflist|30em}}
==External links==
* [https://www.nist.gov/pml/div688/times.cfm NIST FAQ on time]
* [https://longtailworld.blogspot.com/2006/04/japan1212am-is-noon-in-japan.html 12am is noon in Japan]
{{Time Topics}}
{{Time measurement and standards}}
{{DEFAULTSORT:12-Hour Clock}}
[[Category:Date and time representation]]
[[Category:Time measurement systems]]' |
Unified diff of changes made by edit (edit_diff ) | '@@ -164,7 +164,7 @@
It is not always clear what times "12:00 a.m." and "12:00 p.m." denote. From the [[Latin]] words {{lang|la|meridies}} (midday), ''ante'' (before) and ''post'' (after), the term ''{{Lang|la|ante meridiem}}'' (a.m.) means before midday and ''{{Lang|la|post meridiem}}'' (p.m.) means after midday. Since "noon" (midday, {{lang|la|meridies}} (m.)) is neither before nor after itself, the terms a.m. and p.m. do not apply.<ref name=NISTFAQ /> Although "12 m." was suggested as a way to indicate noon, this is seldom done<ref name="chicago" /> and also does not resolve the question of how to indicate midnight.
-''[[The American Heritage Dictionary of the English Language]]'' states "By convention, ''12 AM'' denotes midnight and ''12 PM'' denotes noon. Because of the potential for confusion, it is advisable to use ''12 noon'' and ''12 midnight''".<ref>{{cite dictionary|url=http://ahdictionary.com/word/search.html?q=AM|title=AM|archive-url=https://web.archive.org/web/20140109230904/http://ahdictionary.com/word/search.html?q=AM|archive-date=9 January 2014|url-status=live|dictionary=[[The American Heritage Dictionary of the English Language]]|edition=Fifth|date=2011}}</ref>
+''[[The American Heritage Dictionary of the English Language]]'' states "By convention, ''12 AM'' denotes midnight and ''12 PM'' denotes noon. However this is nonsensical because phrases such as "by midnight on Friday" clearly imply that midnight is at the end of Friday and part of Friday, and therefore midnight is after midday ON FRIDAY, hence to call it "am" (before midday) would be nonsensical. Because of the potential for confusion, it is advisable to use ''12 noon'' and ''12 midnight''".<ref>{{cite dictionary|url=http://ahdictionary.com/word/search.html?q=AM|title=AM|archive-url=https://web.archive.org/web/20140109230904/http://ahdictionary.com/word/search.html?q=AM|archive-date=9 January 2014|url-status=live|dictionary=[[The American Heritage Dictionary of the English Language]]|edition=Fifth|date=2011}}</ref>
-E. G. Richards in his book ''Mapping Time'' (1999) provided a diagram in which 12 a.m. means noon and 12 p.m. means midnight.<ref>{{cite book|last=Richards|first=E. G.|title=Mapping Time: the Calendar and its History|publisher=[[Oxford University Press]]|date=1999|page=289}}</ref>
+E. G. Richards in his book ''Mapping Time'' (1999) provided a diagram in which 12 a.m. means noon and 12 p.m. means midnight.<ref>{{cite book|last=Richards|first=E. G.|title=Mapping Time: the Calendar and its History|publisher=[[Oxford University Press]]|date=1999|page=289}}</ref> This usage aligns with the usage that "by midnight on Friday" means that midnight on Friday is part of Friday (not Saturday) and because it is after noon it is post meridiem ie pm.
Historically, the style manual of the [[United States Government Printing Office]] used 12 a.m. for noon and 12 p.m. for midnight until its 2008 edition. At this point it reversed these designations<ref name="GPO2000" /><ref name="GPO2008" /> and then retained that change in its 2016 revision.<ref>{{cite web|url=https://www.govinfo.gov/features/new-edition-gpo-style-manual|title=GPO Style Manual. 2016. p.236|website=govinfo.gov| date=12 January 2017 |access-date=16 March 2018|archive-url=https://web.archive.org/web/20180317035857/https://www.govinfo.gov/features/new-edition-gpo-style-manual|archive-date=17 March 2018|url-status=live}}</ref>
' |
New page size (new_size ) | 33186 |
Old page size (old_size ) | 32745 |
Size change in edit (edit_delta ) | 441 |
Lines added in edit (added_lines ) | [
0 => '''[[The American Heritage Dictionary of the English Language]]'' states "By convention, ''12 AM'' denotes midnight and ''12 PM'' denotes noon. However this is nonsensical because phrases such as "by midnight on Friday" clearly imply that midnight is at the end of Friday and part of Friday, and therefore midnight is after midday ON FRIDAY, hence to call it "am" (before midday) would be nonsensical. Because of the potential for confusion, it is advisable to use ''12 noon'' and ''12 midnight''".<ref>{{cite dictionary|url=http://ahdictionary.com/word/search.html?q=AM|title=AM|archive-url=https://web.archive.org/web/20140109230904/http://ahdictionary.com/word/search.html?q=AM|archive-date=9 January 2014|url-status=live|dictionary=[[The American Heritage Dictionary of the English Language]]|edition=Fifth|date=2011}}</ref>',
1 => 'E. G. Richards in his book ''Mapping Time'' (1999) provided a diagram in which 12 a.m. means noon and 12 p.m. means midnight.<ref>{{cite book|last=Richards|first=E. G.|title=Mapping Time: the Calendar and its History|publisher=[[Oxford University Press]]|date=1999|page=289}}</ref> This usage aligns with the usage that "by midnight on Friday" means that midnight on Friday is part of Friday (not Saturday) and because it is after noon it is post meridiem ie pm.'
] |
Lines removed in edit (removed_lines ) | [
0 => '''[[The American Heritage Dictionary of the English Language]]'' states "By convention, ''12 AM'' denotes midnight and ''12 PM'' denotes noon. Because of the potential for confusion, it is advisable to use ''12 noon'' and ''12 midnight''".<ref>{{cite dictionary|url=http://ahdictionary.com/word/search.html?q=AM|title=AM|archive-url=https://web.archive.org/web/20140109230904/http://ahdictionary.com/word/search.html?q=AM|archive-date=9 January 2014|url-status=live|dictionary=[[The American Heritage Dictionary of the English Language]]|edition=Fifth|date=2011}}</ref>',
1 => 'E. G. Richards in his book ''Mapping Time'' (1999) provided a diagram in which 12 a.m. means noon and 12 p.m. means midnight.<ref>{{cite book|last=Richards|first=E. G.|title=Mapping Time: the Calendar and its History|publisher=[[Oxford University Press]]|date=1999|page=289}}</ref>'
] |
Whether or not the change was made through a Tor exit node (tor_exit_node ) | false |
Unix timestamp of change (timestamp ) | '1728518758' |