## [time of day](/writing-tips-plus/time-of-day) ## Avertissement Du contenu semblable en français est présenté dans l’article [heure (écriture de l’heure)](/fr/cles-de-la-redaction/heure-ecriture-de-lheure). ## On this page - [Abbrevations “a.m.” and “p.m.”](#abbrevations) - [Time of day](#time-of-day) - [The 24-hour system](#24-hour-system) - [Spans of time](#spans-of-time) - [Additional information](#information) ## Abbreviations “a.m.” and “p.m.” The abbreviation **a.m.** stands for *ante meridiem*, which is Latin for “before midday.” The abbreviation **p.m.** stands for *post meridiem*, which is Latin for “after midday.” Use these abbreviations with numerals only: - 9:00 a.m. \[**not** ninen i n e a.m.\] - 2:00 p.m. \[**not** twot w o p.m.\] These abbreviations are usually written in lower case, with periods and with no internal spacing. - The Prime Minister’s speech will be broadcast at 8:05 p.m.lower case p lower case m on all stations. Regular capitals (A.M., P.M.) or small capitals (A.M., P.M.) are acceptable alternatives in headlines, lists or tables written in upper case. - HeadlineHeadline in all caps: ECLIPSE AT 11:15 A.M. TODAY ## Time of day Except in descriptive text, write the exact time of day in numerical form. Place a non-breaking space between the time and the abbreviation **a.m.** or **p.m.**: - Does the bus arrive at 7 p.m. or 8 p.m.? - Louis is picking me up at 11:25 a.m. In approximate expressions of time and in descriptive text, write out whole, half and quarter hours in words, omitting the abbreviations **a.m.** and **p.m.**: - Drop by around six-thirty for dinner. - We arrived shortly after quarter past seven in the evening. - Time passed excruciatingly slowly—one o’clock, two o’clock, three o’clock … When writing out the time of day in words, use a hyphen between the hour and the minutes, unless the minutes themselves are hyphenated: - I leave for work between eight and eight-thirtyeight hyphen thirty. - Megan usually leaves for work at about eight forty-fiveforty hyphen five. Never use **a.m.** or **p.m.** with the expression **o’clock** or with the words **morning**, **afternoon**, **evening** or **night**. - Sarah doesn’t answer the phone after ten o’clock \[**not** ten p.m. o’clock\]. - The lecture began at 4:30 p.m. \[**or** 4:30 in the afternoon **but not** 4:30 p.m. in the afternoon\]. ## The 24-hour system The 24-hour system is used in specialized fields (such as the military) and in French Canada; it’s also the most commonly used system internationally. Therefore, in documents presented in both official languages, and in international communications, you many want to use the 24-hour system for representing time of day, in accordance with International Standard ISO 8601 and the Treasury Board Federal Identity Program Manual. In this system, the abbreviations **a.m.** and **p.m.** aren’t used. The hour is represented by a two-digit number ranging from 00 to 23 (or 24), while the minutes are represented by a two-digit number ranging from 00 to 59. The colon is used as a separator between hours and minutes: - 00:15zero zero fifteen (12:15 a.m., i.e. 15 minutes after midnight) - 08:00zero eight hundred (8:00 a.m.) - 12:00twelve hundred (noon) - 15:39fifteen hundred thirty-nine (3:39 p.m.) - 24:00twenty-four hundred (midnight) Seconds may also be represented by a two-digit number ranging from 00 to 59, with a colon between minutes and seconds: - 14:12:2614 colon 12 colon 26 (12 minutes and 26 seconds after 2:00 p.m.) To convert time from the 12-hour to the 24-hour system, simply add 12 hours to any hour after midday: Converting time to the 24-hour system | 12-hour system | 24-hour system | 12:00 p.m. / noon | 12:0012 hundred hours | |---|---|---|---| | 1:00 p.m. | 13:0013 hundred hours | | 2:00 p.m. | 14:0014 hundred hours | | 3:00 p.m. | 15:0015 hundred hours | | 4:00 p.m. | 16:0016 hundred hours | | 5:00 p.m. | 17:0017 hundred hours | | 6:00 p.m. | 18:0018 hundred hours | | 7:00 p.m. | 19:0019 hundred hours | | 8:00 p.m. | 20:0020 hundred hours | | 9:00 p.m. | 21:0021 hundred hours | | 10:00 p.m. | 22:0022 hundred hours | | 11:00 p.m. | 23:0023 hundred hours | | 12:00 a.m./ midnight | 00:00 (or 24:00)0 hundred hours or 24 hundred hours | To avoid confusion between 12 a.m. and 12 p.m., use the 24-hour system, or write out the time in words, depending on the context: - For 12 a.m., use **00:00**zero hundred hours (or **24:00**24 hundred hours), or **midnight**. - For 12 p.m., use **12:00**12 hundred hours or **noon**. ## Spans of time Use an en dash (–) to link two figures that represent a continuous time frame. Don’t put a space on either side of the en dash: - Business hours: 9:00 a.m.–5:00 p.m. \[**or** 9 a.m.–5 p.m.\] Don’t use the en dash if the time frame is preceded by the prepositions **from** or **between**: - He was absent from 9 a.m. to 10 a.m. \[**not** from 9 a.m.–10 a.m.\] **From** must be followed by **to**, and **between** by **and**: - Lunch is served between 11:30 a.m. and 2:00 p.m. \[**not** between 11:30 a.m. to 2:00 p.m.\] In informal writing, the first **a.m.** or **p.m.** is sometimes omitted when the time span occurs in the same portion of the day (morning or afternoon). However, in formal writing, you need to repeat the abbreviation: - The office is closed from 1 p.m. to 2 p.m. \[**not** from 1 to 2 p.m.\] ## Additional information - [Elapsed time](/en/writing-tips-plus/elapsed-time) - [Standard time, daylight saving time](/en/writing-tips-plus/daylight-saving-time-daylight-time-standard-time-summer-time) ### Quiz - [Do you have the right time?](/en/quiz/jeu-quiz-do-you-have-the-right-time-eng) ## Avis de droit d’auteur pour l’outil Writing Tips Plus © Sa Majesté le Roi du chef du Canada, représenté par le ou la ministre des Services publics et de l’Approvisionnement Un outil créé et mis en ligne par le Bureau de la traduction, Services publics et Approvisionnement Canada ## Rechercher par thèmes connexes Vous voulez en apprendre davantage sur un thème abordé dans cette page? Cliquez sur un lien ci-dessous pour voir toutes les pages du Portail linguistique du Canada portant sur le thème choisi. Les résultats de recherche s’afficheront dans le [Navigateur linguistique](/fr/navigateur-navigator). - [Abbreviations, acronyms and symbols](/fr/navigateur-navigator?search_api_fulltext=-&field_writing_tools=All&sort_by=views&f%5B1%5D=navigateur_navigator_english_theme%3A447#navigateur-navigator-resultats-results) - [Abbreviations](/fr/navigateur-navigator?search_api_fulltext=-&field_writing_tools=All&sort_by=views&f%5B0%5D=navigateur_navigator_english_theme%3A447&f%5B1%5D=navigateur_navigator_english_theme%3A448#navigateur-navigator-resultats-results) - [Writing conventions](/fr/navigateur-navigator?search_api_fulltext=-&field_writing_tools=All&sort_by=views&f%5B1%5D=navigateur_navigator_english_theme%3A512#navigateur-navigator-resultats-results) - [Numerical expressions](/fr/navigateur-navigator?search_api_fulltext=-&field_writing_tools=All&sort_by=views&f%5B0%5D=navigateur_navigator_english_theme%3A512&f%5B1%5D=navigateur_navigator_english_theme%3A515#navigateur-navigator-resultats-results) ## Liens connexes - [Writing Tips Plus](/fr/writing-tips-plus/index-fra) (page d’accueil) - [Outils d’aide à la rédaction](/fr/outils-tools/index-fra) - [Navigateur linguistique](/fr/navigateur-navigator) (permet de trouver rapidement des conseils linguistiques) - [TERMIUM Plus®](http://www.btb.termiumplus.gc.ca/tpv2alpha/alpha-fra.html?lang=fra)