# Wikipedia:Manual of Style/Dates and numbers

(Redirected from Wikipedia:$) Jump to: navigation, search "WP:NUMBERS" redirects here. For the Number Wikiproject, see Wikipedia:WikiProject Numbers. For the notability guideline, see Wikipedia:Notability (numbers). This page guides the presentation of numbers, dates, times, measurements, currencies, coordinates, and similar material in articles. Its aim is to promote clarity and cohesion; this is especially important within an article. The goal is to make the whole encyclopedia easier and more intuitive to use. Where this manual provides options, consistency should be maintained within an article unless there is a good reason to do otherwise. The Arbitration Committee has ruled that editors should not change an article from one guideline-defined style to another without a substantial reason unrelated to mere choice of style, and that revert-warring over optional styles is unacceptable.[1] If discussion cannot determine which style to use in an article, defer to the style used by the first major contributor. ## General notes ### Quotations, titles, etc. See also: WP:MOSQUOTE Quotations, titles of books and articles, and similar "imported" text should be faithfully reproduced, even if they employ formats or units inconsistent with these guidelines or with other formats in the same article. If necessary, clarify via [bracketed interpolation], article text, or footnotes. • It is acceptable to change other date formats in the same article to provide consistency, so long as those changes would otherwise be acceptable. ### Non-breaking spaces Guidance on the use of non-breaking spaces ("hard spaces") – &nbsp;, {{nbsp}}, &thinsp;, {{thinsp}} – is given in some sections below; {{nowrap}} may also be useful in controlling linebreaks in some situations. Not all situations in which hard spaces or {{nowrap}} may be appropriate are described. For further information see Wikipedia:Manual of Style § Non-breaking spaces and Wikipedia:Line-break handling. ## Chronological items ### Statements likely to become outdated Except on pages updated regularly (e.g. the "Current events" portal), terms such as now, currently, to date, so far, soon, and recently should usually be avoided in favor of phrases such as during the 1990s, since 2010, and in August 1969. For current and future events, use phrases like as of April 2017 or since the beginning of 2017 to signal the time-dependence of the information. Using {{as of|2017}} will produce the text As of 2017 and adds the article to a category flagging it for periodic review. A full date is specified with {{as of|2017|04|25}}. However, do not replace since the beginning of 2005 with {{as of|2005}} because some information (the beginning of 2005) would be lost; in such circumstances, use advanced features of {{as of}} such as {{as of|2005|alt=since the beginning of 2005}}. Relative-time expressions are acceptable for very long periods, such as geological epochs: Humans diverged from other primates long ago, but only recently developed state legislatures. ### Time of day Context determines whether the 12- or 24-hour clock is used; in both, colons separate hours, minutes and seconds (e.g. 1:38:09 pm or 13:38:09). • 12-hour clock times end with dotted or undotted lower-case a.m. or p.m., or am or pm, preceded by a non-breaking space, e.g. 2:30 p.m. or 2:30 pm (markup: 2:30{{nbsp}}p.m. or 2:30{{nbsp}}pm), not 2:30p.m. or 2:30pm. Hours should not have a leading zero (e.g. 2:30 p.m., not 02:30 p.m.). Usually, use noon and midnight rather than 12 pm and 12 am; whether "midnight" refers to the start or the end of a date should be explicitly specified unless clear from the context. • 24-hour clock times have no a.m., p.m., noon or midnight suffix. Hours under 10 should have a leading zero (e.g. 08:15). The time 00:00 refers to midnight at the start of a date, 12:00 to noon, and 24:00 to midnight at the end of a date, but 24 should not be used for the first hour of the next day (e.g. use 00:10 for ten minutes after midnight, not 24:10). The numerical elements of times-of-day are figures (12:45 p.m.) rather than words (twelve forty-five p.m.) though conventional terms such as noon and midnight are acceptable (taking care, with the latter, to avoid possible date ambiguity in constructions such as midnight on July 17). #### Time zones Give dates and times appropriate to the time zone where an event took place. For example, the date of the attack on Pearl Harbor should be December 7, 1941 (Hawaii time/​date). Give priority to the place at which the event had its most significant effects; for example, if a hacker based in China attacked a Pentagon computer in the US, use the time zone for the Pentagon, where the attack had its effect. In some cases the best solution may be to add the date and time in Coordinated Universal Time (UTC). For example: • 8 p.m. Eastern Standard Time on January 15, 2001 (01:00 UTC, January 16) Alternatively, include just the UTC offset: • 21:00 British Summer Time (UTC+1) on 27 July 2012 Rarely, the time zone in which a historical event took place has since changed; for example, China to 1949 was divided into five time zones, whereas all of modern China is UTC+8. Similarly, the term "UTC" is not appropriate for dates before this system was adopted in 1960;[2] Universal Time (UT) is the appropriate term for the mean time at the prime meridian (Greenwich) when it is unnecessary to specify the precise definition of the time scale. Be sure to show the UTC or offset appropriate to the clock time in use at the time of the event, not the modern time zone, if they differ. ### Dates, months and years These requirements do not apply to dates in quotations or titles; . Special rules apply to citations; . #### Formats Acceptable date formats General use Only where brevity is helpful (refs,[3] tables, infoboxes, etc.) Comments 2 August 2001 2 Aug 2001 August 2, 2001 Aug 2, 2001 A comma follows the year unless followed by other punctuation:[4] • The weather on March 12, 2005, was clear and warm • Everyone remembers July 21, 1969 – when man first landed on the Moon 2 August 2 Aug Omit year only where there is no risk of ambiguity: • The 2012 London Olympics ran from 25 July to 12 August • January 1 is New Year's Day August 2 Aug 2 No equivalent for general use 2001-08-02 Use yyyy-mm-dd format only with Gregorian dates from 1583 onward.[5] August 2001 Aug 2001 Unacceptable date formats (except in external titles and quotes) Unacceptable Acceptable Comments Aug. 2 Aug 2 Do not add a dot to the day or to an abbreviated month[7] 9. June 9 June or June 9 9 june june 9 Months are capitalized 9th June June 9th the 9th of June Do not use ordinals (1st, 2nd, 3rd, etc.) 09 June June 09 Do not "zero-pad" month or day, except in all-numeric (yyyy-mm-dd) format 2007-4-15 2007-04-15 2007/04/15 Do not use separators other than hyphen 07-04-15 Do not abbreviate year to two digits 15-04-2007 04-15-2007 Do not use dd-mm-yyyy, mm-dd-yyyy or yyyy-dd-mm formats, as they are ambiguous for some dates[8] 7/2001 7-2001 07-2001 2001-07 2001 July July of 2001 July 2001 Do not use these formats. July, 2001 No comma between month and year 3 July, 2001 3 July 2001 July 3 2001 July 3, 2001 Comma required between day and year the '97 elections the 97 elections the 1997 elections Do not abbreviate year Copyright MMII Copyright 2002 Roman numerals are not normally used for dates Two thousand one 2001 Years and days of the month are not normally written in words the first of May May the first May 1 or 1 May June 0622 June 622 Do not zero-pad years sold in the year 1995 sold in 1995 Use "in the year" only where needed for clarity (About 1800 ships arrived in the year 1801) ##### Consistency • Dates in article body text should all use the same format: She fell ill on 25 June 2005 and died on 28 June, but not She fell ill on 25 June 2005 and died on June 28. • Publication dates in an article's citations should all use the same format, which may be: • the format used in the article body text, • an abbreviated format from the "Acceptable date formats" table, provided the day and month elements are in the same order as in dates in the article body, or • the format expected in the citation style being used (however, all-numeric date formats other than yyyy-mm-dd must still be avoided). For example, publication dates within a single article might be in one, but only one, of these formats (among others): Jones, J. (20 September 2008) Jones, J. (September 20, 2008) • Access and archive dates in an article's citations should all use the same format, which may be: • the format used for publication dates in the article; • the format expected in the citation style adopted in the article (e.g. 20 Sep 2008); or • yyyy-mm-dd For example, access/archive dates within a single article might be in one, but only one, of these formats (among others): Jones, J. (September 20, 2008) ... Retrieved February 5, 2009. Jones, J. (20 Sep 2008) ... Retrieved 5 Feb 2009. Jones, J. (20 September 2008) ... Retrieved 2009-02-05. When a citation style does not expect differing date formats, it is permissible to normalize publication dates to the article body text date format, and/or access/archive dates to either, with date consistency being preferred. ##### Strong national ties to a topic • Articles on topics with strong ties to a particular English-speaking country should generally use the date format most commonly used in that nation. For the United States this is (for example) July 4, 1976; for most other English-speaking countries it is 4 July 1976 • Articles related to Canada may use either format with (as always) consistency within each article. (See § Retaining existing format, below.) • In some topic areas the customary format differs from the usual national one: for example, articles on the modern U.S. military, including U.S. military biographical articles, use day-before-month, in accordance with U.S. military usage. ##### Retaining existing format • If an article has evolved using predominantly one format, the whole article should conform to it, unless there are reasons for changing it based on strong national ties to the topic or consensus on the article's talk page. • The date format chosen by the first major contributor in the early stages of an article should continue to be used, unless there is reason to change it based on strong national ties to the topic or consensus on the article's talk page. • Where an article has shown no clear sign of which format is used, the first person to insert a date is equivalent to "the first major contributor". #### Era style • The default calendar era is the Western Dionysian era system, a year numbering system also known as the Western Christian era (represented by BC and AD), or the Common Era (represented by BCE and CE). • BC and AD are the traditional ways of designating eras. BCE and CE are common in some scholarly texts and in certain topic areas. Either convention may be appropriate for use in Wikipedia articles. • Use either the BC–AD or the BCE–CE notation consistently within the same article. Exception: do not change direct quotations, titles, etc. • Do not change the established era style in an article unless there are reasons specific to its content. Seek consensus on the talk page before making the change. Open the discussion under a subhead that uses the word "era". Briefly state why the style is inappropriate for the article in question. A personal or categorical preference for one era style over the other is not justification for making a change. • BCE and CE or BC and AD are written in upper case, unspaced, without a period (full point, .), and separated from the numeric year by a space (5 BC, not 5BC). It is advisable to use a non-breaking space. • AD may appear before or after a year (AD 106, 106 AD); the other abbreviations appear only after (106 CE, 3700 BCE, 3700 BC). • In general, do not use CE or AD unless required to avoid ambiguity (e.g. The Norman Conquest took place in 1066 not 1066 CE nor AD 1066) or awkwardness (January 1, 1 AD not January 1, 1). On the other hand, Plotinus lived at the end of the 3rd century AD will avoid confusion. Also, in He did not become king until 55 CE the era marker makes it clear that 55 does not refer to the person's age (or write He did not become king until the year 55). If the era is shown for the initial date in a range, then use it for the final date as well: not from 450 BCE to 200 but from 450 to 200 BCE or from 450 BCE to 200 BCE (and definitely from 100 BCE to 200 CE). (See § Ranges, below.) • Uncalibrated (bce) radiocarbon dates: Calibrated and uncalibrated dates can diverge widely, and some sources distinguish the two only via BCE or BC (for calibrated dates) versus bce, bc or b.c. (uncalibrated). Avoid giving uncalibrated dates except in direct quotations, and even then a footnote or square-bracketed note [like this] should note that the date is uncalibrated or (ideally) give the calibrated date. • BP or YBP: In scientific and academic contexts, BP (before present) or YBP (years before present) are often used. (Present in this context conventionally refers to January 1, 1950.) Write 3000 years BP or 3000 YBP or 3000 years before present but not forms such as 3000 before present and 3000 years before the present. If one of the abbreviated forms is used, link to Before present on first use: The Jones artifact was dated to 4000 YBP, the Smith artifact to 5000 YBP. • Other era systems may be appropriate in an article. In such cases, dates should be followed by a conversion to Dionysian (or vice versa) and the first instance should be linked: Qasr-al-Khalifa was built in 221 AH (836 CE), or in 836 AD (221 AH). • Astronomical year numbering follows the Common Era and does not require conversion, but the first instance of a non-positive year should still be linked: The March equinox passed into Pisces in year −67. #### Julian and Gregorian calendars A date can be given in any appropriate calendar, as long as it is (at the minimum) given in the Julian calendar or the Gregorian calendar or both, as described below. For example, an article on the early history of Islam may give dates in both Islamic and Julian calendars. Where a calendar other than the Julian or Gregorian is used, the article must make this clear. • Current events are dated using the Gregorian calendar. • Dates of events in countries using the Gregorian calendar at that time are given in the Gregorian calendar. This includes some of the Continent of Europe from 1582, the British Empire from 14 September 1752, and Russia from 14 February 1918 . • Dates before 15 October 1582 (when the Gregorian calendar was first adopted in some places) are normally given in the Julian calendar. The Julian day and month should not be converted to the Gregorian calendar, but the start of the Julian year should be assumed to be 1 January (see below for more details). • Dates for Roman history before 45 BC are given in the Roman calendar, which was neither Julian nor Gregorian. When (rarely) the Julian equivalent is certain, it may be included. • For dates in early Egyptian and Mesopotamian history, Julian or Gregorian equivalents are often uncertain. Follow the consensus of reliable sources, or indicate their divergence. The dating method used should follow that used by reliable secondary sources (or if reliable sources disagree, that used most commonly, with an explanatory footnote). At some places and times, the new year began on a date other than 1 January. For example, in England and its colonies until 1752, the year began on Annunciation Day, 25 March; see the New Year article for other styles. In writing about historical events, however, years should be assumed to have begun on 1 January (see the example of the execution of Charles I in "Differences in the start of the year"); if there is reason to use another start-of-year date, this should be noted. If there is a need to mention Old or New Style dates in an article (as in the Glorious Revolution), a footnote should be provided on the first usage, stating whether the New Style refers to a start of year adjustment or to the Gregorian calendar (it can mean either). #### Ranges Note: A change from a preference for two digits, to a preference for four digits, on the right side of year–year ranges was implemented in July 2016 per this RFC. • Use a dash, or a word such as from or between, but not both: from 1881 to 1886 (not from 1881–1886); between June 1 and July 3 (not between June 1 – July 3) • A simple year–year range is written using an en dash (&ndash; or {{ndash}}) not a hyphen or slash; this dash is usually unspaced (that is, with no space on either side); and the range's end year is usually given in full: • 1881–1886; 1881–1992 (not 1881–86; 1881 – 1992) Markup: 1881{{ndash}}1886 or 1881&ndash;1886 • Two-digit ending years (1881–82, but never 1881–882 or 1881–2) may be used in any of the following cases: (1) two consecutive years; (2) infoboxes and tables where space is limited (using a single format consistently in any given table column); and (3) in certain topic areas if there is a very good reason, such as matching the established convention of reliable sources. • The slash notation (2005/2006) may be used to signify a fiscal year or other special period, if that convention is used in reliable sources. • Other "simple" ranges use an unspaced en dash as well: • day–day: 5–7 January 1979; January 5–7, 1979; elections were held March 5–8 • month–month: the 1940 peak period was May–July; the peak period was May–July 1940; (but the peak period was May 1940 – July 1940 uses a spaced en dash; see below) • If at least one of the items on either side of the en dash contains a space, then a spaced en dash ({{snd}}) is used: • between specific dates in different months: They travelled June 3 – August 18, 1952; They travelled 3 June – 18 August 1952 • between dates in different years: Charles Robert Darwin (12 February 1809 – 19 April 1882) was an English naturalist ... Markup: 12{{nbsp}}February 1809{{snd}}19{{nbsp}}April 1882 or 12&nbsp;February 1809&nbsp;&ndash; 19&nbsp;April 1882 Abraham Lincoln (February 12, 1809 – April 15, 1865) was the 16th President of ... • between months in different years: The exception was in force August 1892 – January 1903; The Ghent Incursion (March 1822 – January 1, 1823) was ended by the New Year's Treaty Markup: March 1822{{snd}}January{{nbsp}}1, 1823 or March 1822&nbsp;&ndash; January&nbsp;1, 1823 • Constructions such as 1982–present (with unspaced ndash), January 1, 2011 – present (spaced ndash), or January 2011 – present (spaced ndash) may be used where appropriate, but other constructions may be more appropriate in prose . In tables and infoboxes where space is limited, pres. may be used (1982–pres.). Do not use incomplete-looking constructions such as 1982– and 1982–... . • For a person still living: Serena Williams (born September 26, 1981) is a ..., not (September 26, 1981 – ) or (born on September 26, 1981). Do not use * to indicate born; use b. only where space is limited e.g. tables and infoboxes; use either born or b. consistently in any given table column. • Where birthdate is unknown: John Smith (died May 1, 1622) ... or John Smith (died 1622) ... Do not use † to indicate died; use d. only where space is limited, with consistency within any given table column. • An overnight period may be expressed using a slash between two contiguous dates: the night raids of 30/31 May 1942 or raids of 31 May / 1 June 1942. Or use an en dash: (unspaced) raids of 30–31 May 1942; (spaced) raids of 31 May – 1 June 1942. • The {{Age}} template can keep ages current in infoboxes and so on: • {{age|1989|7|23}} returns: 27 • {{age|1989|7|23}}-year-old returns: 27-year-old • {{age|1989|7|23}} years old returns: 27 years old #### Uncertain, incomplete, or approximate dates • To indicate "around", "approximately", or "about", the use of the spaced, unitalicised form c. 1291 (or the {{circa}} template) is preferred over circa, ca, ca., approximately, or approx.: • At the birth of Roger Bacon (c. 1214) ... • John Sayer (c. 1750 – 2 October 1818) ... • the Igehalkid dynasty of Elam, c. 1400 BC ... • Where both endpoints of a range are approximate, c. should appear before each date (the two-argument form of {{circa}} does this): • Dionysius Exiguus (c. 470 – c. 540) ... (not Dionysius Exiguus (c. 470 – 540) ...) • Rameses III (reigned c. 1180 – c. 1150 BCE) ... (not Rameses III (reigned c. 1180 – 1150 BCE) ...) • Where birth/death limits have been inferred from known dates of activity: • Offa of Mercia (before 734 – 26 July 796) ... • Robert Menli Lyon (1789 – after 1863) ... • Ambrose Gwinnett Bierce (June 24, 1842 – after December 26, 1913) ... • When a person is known to have been active ("flourishing") during certain years, fl., [[Floruit|fl.]], or {{fl.}} may be used: • Jacobus Flori (fl. 1571–1588) ... The linked forms should not be used on disambiguation pages, and "active" followed by the range is a better alternative for occupations not relating to the composition of works, whether it be musical, grammatical, historical, or any other such work. • When a date is known to be either of two years (e.g. from a regnal or AH year conversion, or a known age at death): • Anne Smith (born 1912 or 1913; died 2013) ... • Other forms of uncertainty should be expressed in words, either in article text or in a footnote: April 14, 1224 (unattested date). Do not use a question mark (1291?), because it fails to communicate the nature of the uncertainty. • Ranges in which c., after, fl. or similar forms appear‍—‌whether on one or both sides‍—‌employ a spaced endash ({{snd}}) and ideally a nonbreaking space should follow very short modifiers such as c. and fl.. Markup: 1896{{snd}}after 1954, {{c.}}{{nbsp}}470{{snd}}{{c.}}{{nbsp}}540, {{c.|470|540}} ### Other #### Days of the week • Days of the week are capitalized (Sunday, Wednesday). #### Seasons • Seasons are uncapitalized (a hot summer) except when personified: Old Man Winter's bleak greys relent as Spring begins to show her colors. • Using seasons to refer to a particular time of year (winter 1995) is ambiguous for two reasons: Unambiguous alternatives include early 1995; the first quarter of 1995; January to March 1995; spent the southern summer in Antarctica. • Referring to a season by name is appropriate when it is part of a formal or conventional name or designation (annual mid-winter festival; the autumn harvest; 2018 Winter Olympics; Times Fall Books Supplement; Details appeared in Quarterly Review, Summer 2015; The Court's winter term). #### Decades • To refer to a decade as a chronological period per se (not with reference to a social era or cultural phenomenon) always use four digits (the 1980s, but not the 1980's or the 1980‑ies, and definitely not the 1980s'). • Prefixes should be hyphenated (the mid‑1980s; pre‑1960s social attitudes). • For a social era or cultural phenomenon associated with a particular decade: • Two digits (with a preceding apostrophe) may be used as an alternative to four digits, but only if this is a well-established phrase seen in reliable sources (the Roaring '20s, the Gay '90s, condemning the '60s counterculture, but grew up in 1960s Boston, moving to Dallas in 1971, and do not write the 90's; the 90s; or the 90s'). • A third alternative (where seen in reliable sources) is to spell the decade out, capitalized: changing attitudes of the Sixties #### Centuries and millennia • Treat the 1st century AD as years 1–100, the 17th century as 1601–1700, and the second millennium as 1001–2000; similarly, the 1st century BC/BCE was 100–1 BC/BCE, the 17th century was 1700–1601 BC/BCE, and the second millennium 2000–1001 BC/BCE. • The 18th century (1701–1800) and the 1700s (1700–1799) are not the same period. • When using forms such as the 1900s, ensure that there is no ambiguity as to whether the century or just its first decade is meant. • Note that the sequence of years runs ... 2 BC, 1 BC, 1 AD, 2 AD ... – there is no "year 0". • Centuries and millennia are identified using either figures (the 18th century, not XVIII century) or words (the second millennium). When used adjectivally they contain a hyphen (nineteenth-century painting or 19th-century painting). Do not capitalize (the best Nineteenth-century paintings; during the Nineteenth Century). #### Long periods of time • When the term is frequent, combine yr (years) or ya (years ago) with k (thousand): kya, kyr; M (million): Mya, Myr; and b (short-scale billion): bya, byr. (See Year#Abbreviations yr and ya for more information.) • In academic contexts, SI annus-based units are often used: ka (kiloannus), Ma (megaannus), and Ga (gigaannus). (See Year#SI prefix multipliers for more information.) • Show the meaning parenthetically, and consider linking to the appropriate section of the Year article (see links above) on first occurrence and where the use is a standalone topic of interest. In source quotations, use square brackets: "a measured Libby radiocarbon date of 35.1 mya [million years ago] required calibration ..." ## Numbers ### Numbers as figures or words See also information on specific situations, elsewhere in this guideline. Generally, in article text: • Integers from zero to nine are spelled out in words. • Integers greater than nine expressible in one or two words may be expressed either in numerals or in words (16 or sixteen, 84 or eighty-four, 200 or two hundred). Numbers between 21 and 99 are hyphenated (including when part of a larger number): fifty-six or fifty-six thousand but five hundred or five thousand. • Other numbers are given in numerals (3.75, 544) or in forms such as 21 million. Markup: 21{{nbsp}}million • "billion" and "trillion" are understood to represent their short-scale values of 109 (1,000,000,000) and 1012 (1,000,000,000,000), respectively. Keep this in mind when translating articles from non-English Wikipedias, or using material from non-English sources. • M (unspaced) or bn (unspaced) respectively may be used for "million" or "billion" after a number, when the word has been spelled out at the first occurrence (She received £70 million and her son £10M). • SI prefixes and symbols, such as mega- (M), giga- (G) and tera- (T), should be used only with units of measure as appropriate to the field, and not to express large quantities in other contexts (of the population of 1.3G people, 300 megadeaths would be expected). • Sometimes, the variety of English used in an article may necessitate the use of a numbering system other than the Western thousands-based system. For example, the South Asian numbering system is conventionally used in South Asian English. In those situations, link the first spelled-out instance of each quantity (e.g. [[crore]], which yields crore). (If no instances are spelled out, provide a note after the first instance directing the reader to the article about the numbering system.) Also, provide a conversion to Western numbers for the first instance of each quantity, and provide conversions for subsequent instances if they do not overwhelm the content of the article. For example, write three crore (thirty million). Group digits in Western thousands-based style (e.g., 30,000,000; not 3,00,00,000); see § Delimiting (grouping of digits), below. (Note that the variety of English does not uniquely determine the method of numbering in an article. Other considerations, such as conventions used in mathematics, science and engineering, may also apply, and the choice and order of formats and conversions is a matter of editorial discretion and consensus.) Notes and exceptions: • In tables and infoboxes, quantities are expressed in figures (Years in office: 5); but numbers within a table's explanatory text and comments follow the general rule. • Numbers in mathematical formulae are never spelled out (3 < π < 22/7, not three < π < 22 sevenths). • Comparable quantities should be all spelled out or all in figures: • five cats and thirty-two dogs, not five cats and 32 dogs • 86 men and 103 women, not eighty-six men and 103 women • There were 3 winners and 206 losers, even though 3 would normally be given as three; or Three won and two hundred six lost (or two hundred and six in British English), even though two hundred six would normally be given as 206); but not There were three winners and 206 losers. • But adjacent quantities not comparable should usually be in different formats: twelve 90-minute volumes or 12 ninety-minute volumes, not 12 90-minute volumes or twelve ninety-minute volumes. • Avoid awkward juxtapositions: On February 25, 2011, twenty-one more were chosen, not On February 25, 2011, 21 more were chosen. • Personal ages are typically stated in figures (8-year-old child) except for large, approximate values (69-million-year-old fossil). • Sometimes figures and words carry different meanings; for example Every locker except one was searched implies there is a single exception (without specifying which), while Every locker except 1 was searched means that only locker number 1 was not searched. • Proper names, technical terms, and the like are never altered: Seven Samurai; The Sixth Sense; 5 Channel Street; Channel 5; Chanel No. 5; Fourth Estate; The Third Man; Second Judicial District; First Amendment; Zero Hour!; Less Than Zero • Avoid beginning a sentence with figures: • Not There were many matches. 23 ended in a draw, but There were many matches; 23 ended in a draw or There were many matches. Twenty-three ended in a draw. • Not 1945 and 1950 saw crucial elections (nor Nineteen forty-five and 1950 saw crucial elections – because comparable numbers should be both written in words or both in figures) but The elections of 1945 and 1950 were crucial. • Exception: Where a proper name, technical term, etc., itself beginning with a numeral, opens the sentence (1-Naphthylamine is typically synthesized via the Feldenshlager–Glockenspiel process) although this can usually be avoided by rewording (Feldenshlager–Glockenspiel is the process typically used in the synthesis of 1-naphthylamine). ### Ordinals ### Singular versus plural • Nouns following simple fractions are singular (He took 14 dose; net change in score was −12 point; 32 dose). • Nouns following mixed numbers are plural (suicide victim knew even 112 doses could be fatal; continued another 434 miles). • Nouns following the lone, unsigned digit 1 are singular, but those following other decimal numbers (i.e. base-10 numbers not involving fractions) are plural (increased 0.7 percentage points; 365.25 days; paid 5 dollars per work hour, 1 dollar per travel hour, 0 dollars per standby hour; increased by 1 point but net change +1 points; net change −1 points; net change 1.0 points). • The same rules apply to numbers given in words (one dose; one and one-half doses; zero dollars; net change negative one points). ### Fractions and ratios • Spelled-out fractions are hyphenated: seven-eighths. • Where numerator and denominator can each be expressed in one word, a fraction is usually spelled out (e.g. a two-thirds majority; moved one-quarter mile); use figures if a fraction appears with a symbol (e.g. 14 mi – markup: {{frac|1|4}}&nbsp;mi, not a quarter of a mi or one-quarter mi). • Mixed numbers are usually given in figures, unspaced (not Fellini's film 8 12 or 8-12 but Fellini's film 8 12 – markup: {{frac|8|1|2}}). In any case the integer and fractional parts should be consistent (not nine and 12). • Metric (SI) measurements generally use decimals, not fractions (5.25 mm, not 514 mm). • Non-metric (imperial and US customary) measurements may use fractions or decimals (514 inches; 5.25 inches); the practice of reliable sources should be followed, and within-article consistency is desirable. • In science and mathematics articles mixed numbers are rarely used (not 113 times the original voltage, but 4/3 the original) and use of {{frac}} is discouraged in favor of one of these styles: • ${\displaystyle \textstyle {\frac {1}{2}}}$ – markup: <math>\textstyle\frac{1}{2}[/itex] • 1/2 – markup: {{sfrac|1|2}} • 1/2 – markup: 1/2 • Do not use special characters such as "½" (deprecated markup: &frac12; or &#189;). • Ordinal suffixes such as -th should not be used with fractions expressed in figures (not each US state has 1/50th of the Senate's votes1/8th mile, but one-fiftieth of the Senate's votes1/8 mileone-eighth mile). • Dimensionless ratios (i.e. those not incorporating units) are given using numerals and a colon, or numbers-as-words and to: favored by a 3:1 ratio or a three-to-one ratio, but not a 3/1 ratio or a 3–1 ratio. Use a "spaced" colon when a decimal point is present (a 3.5 : 1 ratio – markup: a 3.5&nbsp;:&nbsp;1 ratio). Do not use the colon form where units are involved (dissolve using a 3 ml:1 g ratio)‍—‌instead see ratios section of table at § Unit names and symbols, below. ### Decimals • A period/full point (.), never a comma, is used as the decimal point (6.57, not 6,57). • Numbers between −1 and +1 require a leading zero (0.02, not .02); exceptions are sporting performance averages (.430 batting average) and commonly used terms such as .22 caliber. • Indicate repeating digits with an overbar e.g. 14.31{{overline|28}} gives 14.3128. (Consider explaining this notation on first use.) Do not write e.g. 14.31(28) because it resembles notations for § Uncertainty. #### Grouping of digits For technical reasons, "Project:Digits" redirects here. For the Microsoft Research project, see Project Digits. • Digits should be grouped and separated either by commas or narrow gaps (never a period/full point). Grouping with commas • Left of the decimal point, five or more digits are grouped into threes separated by commas (e.g. 12,200, 255,200 km, 8,274,527th, 186,400). • Numbers with exactly four digits left of the decimal point may optionally be grouped (either 1,250 or 1250), provided that this is consistent within each article. • When commas are used left of the decimal point, digits right of the decimal point are not grouped (i.e. should be given as an unbroken string). • Markup: {{formatnum:}} produces this formatting. Grouping with narrow gaps • Digits are grouped both sides of the decimal point (e.g. 6543210.123456, 520.01234 °C, 101325/760). • Digits are generally grouped into threes. Right of the decimal point, usual practice is to have a final group of four instead of a lone digit (e.g. 99.1234567 or 99.1234567). In mathematics-oriented articles long strings may be grouped into fives (e.g. 3.14159265358979323846...). • This style is especially recommended for articles related to science, technology, engineering or mathematics. • Markup: Templates {{val}} or {{gaps}} may be used to produce this formatting. Note that use of any space character in numbers, including non-breaking space, is problematic for screen readers. (See §Non-breaking spaces.) Screen readers read out each group of digits as separate numbers (e.g. 30&thinsp;000 is read as "thirty zero zero zero".) • Delimiting style should be consistent throughout a given article. • Either use commas or narrow gaps, but not both in the same article. • Either group the thousands in a four-digit number or do not, but not mixed use in the same article. • However, grouping by threes and fives may coexist. • An exception is made for four-digit page numbers or four-digit calendar years. These should never be grouped (not sailed in 1,492, though dynasty collapsed around 10,400 BC or by 13727 AD, Vega will be the northern pole star). ### Percentages • In the body of non-scientific/non-technical articles, percent (American English) or per cent (British English) are commonly used: 10 percent; ten percent; 4.5 per cent. Ranges are written ten to twelve per cent or ten to twelve percent, not ten–twelve per cent or ten to twelve %. • In the body of scientific/​technical articles, and in tables and infoboxes of any article, the symbol % (unspaced) is more common: 3%, not 3 % or three %. Ranges: 10–12%, not 10%–12% or 10 to 12%. • When expressing the difference between two percentages, do not confuse a percentage change with a change in percentage points. ### Scientific and engineering notation • Scientific notation always has a single nonzero digit to the left of the point: not 60.22×1022, but 6.022×1023. • Engineering notation is similar, but adjusted so that the exponent is a multiple of three: 602.2×1021. • Avoid mixing scientific and engineering notations (A 2.23×102 m2 region covered by 234.0×106 grains of sand). • In a table column (or other presentation) in which all values can be expressed with a single power of 10, consider giving e.g. ×107 once in the column header, and omitting it in the individual entries. (Markup: {{e|7}}) • In both notations, the number of digits indicates the precision. For example, 5×103 means rounded to the nearest thousand; 5.0×103 to the nearest hundred; 5.00×103 to the nearest ten; and 5.000×103 to the nearest unit. Markup: {{val}} and {{e}} may be used to format exponential notation. ### Uncertainty and rounding • Where explicit uncertainty information (such as a margin of error) is available and appropriate for inclusion, it may be written in various ways: • (1.534 ± 0.035) × 1023 m • 12.34 m2 ± 5% (not used with scientific notation) • 15.34 +0.43 −0.23 × 1023 m • 1.604(48) × 10−4 J (equivalent to (1.604 ± 0.048) × 10−4 J)[9] • Polls estimated Jones's share of the vote would be 55 percent, give or take about 3 percent Markup: {{+-}}, {{su}}, and {{val}} may be used to format uncertainties. • Where explicit uncertainty is unavailable (or is unimportant for the article's purposes) round to an appropriate number of significant digits; the precision presented should usually be conservative. Precise values (often given in sources for formal or matter-of-record reasons) should be used only where stable and appropriate to the context, or significant in themselves for some special reason. • The speed of light is defined to be 299,792,458 m/s but Particle velocities eventually reached almost two-thirds the 300-million-metre-per-second speed of light. • checks worth$250 (equivalent to $1,800 in 2016) (not$1,845.38)
•   The city's 1920 population was 10,000 (not population was 9,996 – an official figure unlikely to be accurate at full precision)
but The town was ineligible because its official census figure (9,996) fell short of the statutory minimum of ten thousand (unusual case in which the full-precision official population figure is helpful to readers)
•   The accident killed 337 passengers and crew, and three airport workers (likely that accurate and precise figures were determined)
•   At least 800 persons died in the ensuing mudslides (unlikely that any precise number can be accurate, even if an official figure is issued)
or Officials listed 835 deaths, but the Red Cross said dozens more may have gone unreported (in reporting conflicting information, give detail sufficient to make the contrast intelligible)

### Currency names

• Do not capitalize the names or denominations of currencies, currency subdivisions, coins and banknotes: not a Five-Dollar bill, four Quarters, and one Penny total six Dollars one Cent but a five-dollar bill, four quarters, and one penny total six dollars one cent. Exception: where otherwise required, as at the start of a sentence or in such forms as Australian dollar.
• To pluralize euro use the standard English plurals (ten euros and fifty cents), not the invariant plurals used for European Union legislation and banknotes (ten euro and fifty cent). For the adjectival form, use a hyphenated singular: (a two-euro pen and a ten-cent coin).
• Link the first occurrence of lesser-known currencies (Mongolian tögrögs).

### Currency symbols

• In general, the first mention of a particular currency should use its full, unambiguous signifier (e.g. A$52), with subsequent references using just the appropriate symbol (e.g.$88), unless this would be unclear. Exceptions:
• In an article referring to multiple currencies represented by the same symbol (e.g. the dollars of the US, Canada, Australia, New Zealand, and other countries – ) use the full signifier (e.g. US$, A$) each time, except (possibly) where a particular context makes this both unnecessary and undesirable.
• In articles entirely on EU-, UK- and/or US-related topics, all occurrences may be shortened (€26, £22 or $34), unless this would be unclear. • The pound sterling is represented by the £ symbol, with one horizontal bar. The double-barred symbol is ambiguous, as it has also been used for the Italian lira and other currencies. For non-British currencies that use pounds or a pound symbol (e.g. the Irish pound, IR£) use the symbol conventionally preferred for that currency. • If there is no common English abbreviation or symbol, follow the ISO 4217 standard. See also List of circulating currencies. ### Formatting • A period (full stop, .) is used as the decimal point – never a comma ($6.57, not $6,57). • For the grouping of digits (e.g. £1,234,567) see § Grouping of digits, above. • Do not place a currency symbol after the accompanying numeric figures (e.g. 123$, 123£, 123€) unless that is the normal convention for that symbol when writing in English: smaller British coins include 1p, 2p, and 5p denominations. Never use forms such as $US123 or$123 (US).
• Currency abbreviations that come before the numeric value are unspaced if they consist of a nonalphabetic symbol only, or end in a symbol (£123;   €123); but spaced if alphabetic (R 75).
• Ranges should be expressed giving the currency signifier just once: $250–300, not$250–$300. • million and billion should be spelled out on first use, and (optionally) abbreviated M or bn (both unspaced) thereafter: She received £70 million and her son £10M; the school's share was$250–300 million, and the charity's $400–450M. • In general, a currency symbol should be accompanied by a numeric amount e.g. not He converted his US$ to A$but He converted his US dollars to Australian dollars or He exchanged the US$100 note for Australian dollars.
• Exceptions may occur in tables and infoboxes where space is limited e.g. Currencies accepted for deposit: US$, SFr, GB£, . It may be appropriate to wikilink such uses, or add an explanatory note. ### Conversions • Conversions of less-familiar currencies may be provided in terms of more familiar currencies – such as the US dollar, euro or pound sterling – using an appropriate rate (which is often not the current exchange rate). Conversions should be in parentheses after the original currency, rounding to avoid false precision (two significant digits is usually sufficient, as most exchange rates fluctuate significantly), with at least the year given as a rough point of conversion rate reference; e.g. Since 2001 the grant has been 10,000,000 Swedish kronor ($1.4M, €1.0M, or £800k as of August 2009), not (\$1,390,570, €971,673 or £848,646).
• For obsolete currencies, provide an equivalent (formatted as a conversion) if possible, in the modern replacement currency (e.g. decimal pounds for historical pre-decimal pounds-and-shillings), or a US-dollar equivalent where there is no modern equivalent.
• In some cases it may be appropriate to provide a conversion accounting for inflation or deflation over time. See {{Inflation}} and {{Inflation-fn}}.

## Common mathematical symbols

• The Insert menu below the editing window gives a more complete list of math symbols, and allows symbols to be inserted without the HTML encoding (e.g. &divide;) shown here.
• Spaces are placed to left and right when a symbol is used with two operands, but no space is used when there is one operand.
• Use {{var}} or <var>...</var> for variable names: {{var|base}} + {{var|ht}} and <var>base</var> + <var>ht</var> both produce base + ht.
• The {{nbsp}} and {{nowrap}} templates may be used to prevent awkward linebreaks.
Common mathematical symbols
Symbol name Example Markup Comments
Plus /
positive
x + y x + y
+y +y
Minus /
negative
xy x &minus; y Do not use hyphen (-) or dashes ({{ndash}} or {{mdash}}).
y &minus;y
Plus-minus /
minus-plus
41.5 ± 0.3 41.5 &plusmn; 0.3
−(±a) = ∓a &minus;(&plusmn;a) = &#8723;a
Multiplication,
cross
x × y x &times; y Do not use the letter x to indicate multiplication. However, an unspaced x may be used as a substitute for "by" in common terms such as 4x4.
Division, obelus x ÷ y x &divide; y
Equal / equals x = y x = y
Not equal xy x &ne; y
Approx. equal π ≈ 3.14 {{pi}} &asymp; 3.14
Less than x < y x &lt; y
Less or equal xy x &le; y
Greater than x > y x &gt; y
Greater or equal xy x &ge; y

## Geographical coordinates

For draft guidance on, and examples of, coordinates for linear features, see Wikipedia:WikiProject Geographical coordinates/Linear.
Quick guide:
Quick how to
To add 57°18′22″N 4°27′32″W﻿ / ﻿57.30611°N 4.45889°W to the top of an article, use {{Coord}}, thus:
{{Coord|57|18|22|N|4|27|32|W|display=title}}

These coordinates are in degrees, minutes, and seconds of arc.

"title" means that the coordinates will be displayed next to the title.

To add 44°06′43″N 87°54′47″W﻿ / ﻿44.112°N 87.913°W to the top of an article, use either
{{Coord|44.112|N|87.913|W|display=title}}

or

{{Coord|44.112|-87.913|display=title}}

These coordinates are in decimal degrees.

• Degrees, minutes and seconds must be separated by a pipe ("|").
• Map datum must be WGS84 (except for off-earth bodies).
• Avoid excessive precision (0.0001° is <11 m, 1″ is <31 m).
• Maintain consistency of decimal places between latitude and longitude.
• Latitude (N/S) must appear before longitude (E/W).
Optional coordinate parameters follow the longitude and are separated by an underscore ("_"):
• dim: dim:N (viewing diameter in metres)
• region: region:R (ISO 3166-1 alpha-2 or ISO 3166-2 code)
• type: type:T (landmark or city(30,000), for example)

Other optional parameters are separated by a pipe ("|"):

• display
|display=inline (the default) to display in the body of the article only,
|display=title to display at the top of the article only, or
|display=inline,title to display in both places.
• name
name=X to label the place on maps (default is PAGENAME)

Thus: {{Coord|44.117|-87.913|dim:30_region:US-WI_type:event

|display=inline,title|name=accident site}}

Use |display=title (or |display=inline,title) once per article, for the subject of the article, where appropriate.

Geographical coordinates on Earth should be entered using a template to standardise the format and to provide a link to maps of the coordinates. As long as the templates are adhered to, a robot performs the functions automatically.

First, obtain the coordinates. Avoid excessive precision.

Two types of template are available:

• {{coord}} offers users a choice of display format through user styles, emits a Geo microformat, and is recognised (in the title position) by the "nearby" feature of Wikipedia's mobile apps and by external service providers such as Google Maps and Google Earth, and Yahoo.
• Infoboxes such as {{Infobox settlement}}, which automatically emit {{Coord}}.

The following formats are available.

• For degrees only (including decimal values): {{coord|dd|N/S|dd|E/W}}
• For degrees/minutes: {{coord|dd|mm|N/S|dd|mm|E/W}}
• For degrees/minutes/seconds: {{coord|dd|mm|ss|N/S|dd|mm|ss|E/W}}

where:

• dd, mm, ss are the degrees, minutes and seconds, respectively;
• N/S is either N for northern or S for southern latitudes;
• E/W is either E for eastern or W for western longitudes;
• negative values may be used in lieu of S and W to denote Southern and Western Hemispheres

For example:

For the city of Oslo, located at 59° 55′ N, 10° 44′ E:

{{coord|59|55|N|10|44|E}} – which becomes 59°55′N 10°44′E﻿ / ﻿59.917°N 10.733°E

For a country, like Botswana, less precision is appropriate:

{{coord|22|S|24|E}} – which becomes 22°S 24°E﻿ / ﻿22°S 24°E

Higher levels of precision are obtained by using seconds:

{{coord|33|56|24|N|118|24|00|W}} – which becomes 33°56′24″N 118°24′00″W﻿ / ﻿33.94000°N 118.40000°W

Coordinates can be entered as decimal values

{{coord|33.94|S|118.40|W}} – which becomes 33°56′S 118°24′W﻿ / ﻿33.94°S 118.40°W

Increasing or decreasing the number of decimal places controls the precision. Trailing zeros should be used as needed to ensure that both values have the same level of precision.

London Heathrow Airport, Amsterdam, Jan Mayen and Mount Baker are examples of articles that contain geographical coordinates.

Generally, the larger the object being mapped, the less precise the coordinates should be. For example, if just giving the location of a city, precision greater than 100 meters is not needed unless specifying a particular point in the city, for example the central administrative building. Specific buildings or other objects of similar size would justify precisions down to 10 meters or even one meter in some cases (1′′ ~15 m to 30 m, 0.0001° ~5.6 m to 10 m).

The final field, following the E/W, is available for attributes such as type:, region:, or scale: (the codes are documented at Template:Coord/doc#Coordinate parameters).

When adding coordinates, please remove the {{coord missing}} tag from the article, if present.

For more information, see the geographical coordinates WikiProject.

Templates other than {{coord}} should use the following variable names for coordinates: lat_d, lat_m, lat_s, lat_NS, long_d, long_m, long_s, long_EW.

## Notes and references

1. ^
2. ^ CCTF/09-32: Coordinated Universal Time (UTC) (PDF). BIPM. 2009-06-02. p. 3. Retrieved 2015-08-20. This coordination began on January 1, 1960, and the resulting time scale began to be called informally 'Coordinated Universal Time.'
3. ^ Only certain citation styles use abbreviated date formats.
4. ^
5. ^ All-numeric yyyy-mm-dd dates might be assumed to follow the ISO 8601 standard, which mandates the Gregorian calendar. Also, technically all must be four-digit years, but Wikipedia is unlikely to ever need to format a far-future date beyond the year 9999.
6. ^ The routine linking of dates is deprecated. This change was made August 24, 2008, on the basis of this archived discussion. It was ratified in two December 2008 RfCs Wikipedia:Manual of Style/Dates and numbers/Three proposals for change to MOSNUM and Wikipedia:Manual of Style/Dates and numbers/Date Linking RFC
7. ^ Wikipedia talk:Manual of Style/Archive 151 § RFC: Month abbreviations
8. ^ These formats cannot, in general, be distinguished on sight, because there are usages in which 03-04-2007 represents March 4, and other usages in which it represents April 3. In contrast there is no common usage in which 2007-04-03 represents anything other than April 3.
9. ^ The number in parentheses is the numerical value of the standard uncertainty referred to the corresponding last digits of the quoted result –
10. ^ The 0x and 0 prefixes, but not 0b, are borrowed from the C programming language.
11. ^ If there is disagreement about the primary units used in a UK-related article, discuss the matter on the article talk-page, at MOSNUM talk, or both. If consensus cannot be reached, refer to historically stable versions of the article and retain the units used in these as the primary units. Also note the style guides of British publications such as The Times (see archived version, under "Metric").
12. ^ These definitions are consistent with all units of measure mentioned in the SI Brochure (see previous footnote) and with all units of measure catalogued in EU directive 80/181/EEC [1].
13. ^ a b c "Chapter 4: Non-SI units accepted for use with the SI, and units based on fundamental constants (contd.)". SI Brochure: The International System of Units (SI) (8th ed.). BIPM. 2014 [2006]. Retrieved 2015-08-20. Tables 6, 7, 8, and 9 give additional guidance on non-SI units.
14. ^ Wilkins, G. A. (1989). "5.14 Time and angle". IAU Style Manual (PDF). p. S23.
15. ^ "Resolution B2 on the re-definition of the astronomical unit of length" (PDF). International Astronomical Union. 2012. p. 1.
16. ^ Wikipedia follows common practice regarding bytes and other data traditionally quantified using binary prefixes (e.g. mega- and kilo-, meaning 220 and 210 respectively) and their unit symbols (e.g. MB and KB) for RAM and decimal prefixes for most other uses. Despite the IEC's 1998 international standard creating several new binary prefixes (e.g. mebi-, kibi-) to distinguish the meaning of the decimal SI prefixes (e.g. mega- and kilo-, meaning 106 and 103 respectively) from the binary ones, and the subsequent incorporation of these IEC prefixes into the ISO/IEC 80000, consensus on Wikipedia in computing-related contexts currently favours the retention of the more familiar but ambiguous units KB, MB, GB, TB, PB, EB, etc. over use of unambiguous IEC binary prefixes. For detailed discussion, see WT:Manual of Style (dates and numbers)/Archive/Complete rewrite of Units of Measurements (June 2008).