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class="interlanguage-link-target"><span>العربية</span></a></li><li class="interlanguage-link interwiki-bn mw-list-item"><a href="https://bn.wikipedia.org/wiki/%E0%A6%9C%E0%A7%8D%E0%A6%AF%E0%A7%8B%E0%A6%A4%E0%A6%BF%E0%A6%B0%E0%A7%8D%E0%A6%AC%E0%A6%BF%E0%A6%9C%E0%A7%8D%E0%A6%9E%E0%A6%BE%E0%A6%A8%E0%A7%80%E0%A6%AF%E0%A6%BC_%E0%A6%AC%E0%A6%B0%E0%A7%8D%E0%A6%B7_%E0%A6%B8%E0%A6%82%E0%A6%96%E0%A7%8D%E0%A6%AF%E0%A6%BE_%E0%A6%AA%E0%A6%A6%E0%A7%8D%E0%A6%A7%E0%A6%A4%E0%A6%BF" title="জ্যোতির্বিজ্ঞানীয় বর্ষ সংখ্যা পদ্ধতি – Bangla" lang="bn" hreflang="bn" data-title="জ্যোতির্বিজ্ঞানীয় বর্ষ সংখ্যা পদ্ধতি" data-language-autonym="বাংলা" data-language-local-name="Bangla" class="interlanguage-link-target"><span>বাংলা</span></a></li><li class="interlanguage-link interwiki-bh mw-list-item"><a href="https://bh.wikipedia.org/wiki/%E0%A4%96%E0%A4%97%E0%A5%8B%E0%A4%B2%E0%A4%B6%E0%A4%BE%E0%A4%B8%E0%A5%8D%E0%A4%A4%E0%A5%8D%E0%A4%B0%E0%A5%80%E0%A4%AF_%E0%A4%B8%E0%A4%BE%E0%A4%B2" title="खगोलशास्त्रीय साल – Bhojpuri" lang="bh" hreflang="bh" data-title="खगोलशास्त्रीय साल" data-language-autonym="भोजपुरी" data-language-local-name="Bhojpuri" class="interlanguage-link-target"><span>भोजपुरी</span></a></li><li class="interlanguage-link interwiki-ca mw-list-item"><a href="https://ca.wikipedia.org/wiki/Numeraci%C3%B3_astron%C3%B2mica_dels_anys" title="Numeració astronòmica dels anys – Catalan" lang="ca" hreflang="ca" data-title="Numeració astronòmica dels anys" data-language-autonym="Català" data-language-local-name="Catalan" class="interlanguage-link-target"><span>Català</span></a></li><li class="interlanguage-link interwiki-da mw-list-item"><a href="https://da.wikipedia.org/wiki/Astronomisk_tidsregning" title="Astronomisk tidsregning – Danish" lang="da" hreflang="da" data-title="Astronomisk tidsregning" data-language-autonym="Dansk" data-language-local-name="Danish" class="interlanguage-link-target"><span>Dansk</span></a></li><li class="interlanguage-link interwiki-de mw-list-item"><a href="https://de.wikipedia.org/wiki/Astronomische_Jahresz%C3%A4hlung" title="Astronomische Jahreszählung – German" lang="de" hreflang="de" data-title="Astronomische Jahreszählung" data-language-autonym="Deutsch" data-language-local-name="German" class="interlanguage-link-target"><span>Deutsch</span></a></li><li class="interlanguage-link interwiki-el mw-list-item"><a href="https://el.wikipedia.org/wiki/%CE%91%CF%83%CF%84%CF%81%CE%BF%CE%BD%CE%BF%CE%BC%CE%B9%CE%BA%CF%8C_%CF%83%CF%8D%CF%83%CF%84%CE%B7%CE%BC%CE%B1_%CF%87%CF%81%CE%BF%CE%BD%CE%BF%CE%BB%CF%8C%CE%B3%CE%B7%CF%83%CE%B7%CF%82" title="Αστρονομικό σύστημα χρονολόγησης – Greek" lang="el" hreflang="el" data-title="Αστρονομικό σύστημα χρονολόγησης" data-language-autonym="Ελληνικά" data-language-local-name="Greek" class="interlanguage-link-target"><span>Ελληνικά</span></a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/Numeraci%C3%B3n_de_a%C3%B1os_astron%C3%B3mica" title="Numeración de años astronómica – Spanish" lang="es" hreflang="es" data-title="Numeración de años astronómica" data-language-autonym="Español" data-language-local-name="Spanish" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-hr mw-list-item"><a href="https://hr.wikipedia.org/wiki/Astronomsko_brojenje_godina" title="Astronomsko brojenje godina – Croatian" lang="hr" hreflang="hr" data-title="Astronomsko brojenje godina" data-language-autonym="Hrvatski" data-language-local-name="Croatian" class="interlanguage-link-target"><span>Hrvatski</span></a></li><li class="interlanguage-link interwiki-ig mw-list-item"><a href="https://ig.wikipedia.org/wiki/N%E1%BB%8Dmba_af%E1%BB%8D_nke_nd%E1%BB%8B_na-enyocha_mbara_igwe" title="Nọmba afọ nke ndị na-enyocha mbara igwe – Igbo" lang="ig" hreflang="ig" data-title="Nọmba afọ nke ndị na-enyocha mbara igwe" data-language-autonym="Igbo" data-language-local-name="Igbo" class="interlanguage-link-target"><span>Igbo</span></a></li><li class="interlanguage-link interwiki-mk mw-list-item"><a href="https://mk.wikipedia.org/wiki/%D0%90%D1%81%D1%82%D1%80%D0%BE%D0%BD%D0%BE%D0%BC%D1%81%D0%BA%D0%BE_%D0%B1%D1%80%D0%BE%D0%B5%D1%9A%D0%B5_%D0%BD%D0%B0_%D0%B3%D0%BE%D0%B4%D0%B8%D0%BD%D0%B8%D1%82%D0%B5" title="Астрономско броење на годините – Macedonian" lang="mk" hreflang="mk" data-title="Астрономско броење на годините" data-language-autonym="Македонски" data-language-local-name="Macedonian" class="interlanguage-link-target"><span>Македонски</span></a></li><li class="interlanguage-link interwiki-ja mw-list-item"><a href="https://ja.wikipedia.org/wiki/%E5%A4%A9%E6%96%87%E5%AD%A6%E7%9A%84%E7%B4%80%E5%B9%B4%E6%B3%95" title="天文学的紀年法 – Japanese" lang="ja" hreflang="ja" data-title="天文学的紀年法" data-language-autonym="日本語" data-language-local-name="Japanese" class="interlanguage-link-target"><span>日本語</span></a></li><li class="interlanguage-link interwiki-ru mw-list-item"><a href="https://ru.wikipedia.org/wiki/%D0%90%D1%81%D1%82%D1%80%D0%BE%D0%BD%D0%BE%D0%BC%D0%B8%D1%87%D0%B5%D1%81%D0%BA%D0%B0%D1%8F_%D0%B3%D0%BE%D0%B4%D0%BE%D0%B2%D0%B0%D1%8F_%D0%BD%D1%83%D0%BC%D0%B5%D1%80%D0%B0%D1%86%D0%B8%D1%8F" title="Астрономическая годовая нумерация – Russian" lang="ru" hreflang="ru" data-title="Астрономическая годовая нумерация" data-language-autonym="Русский" data-language-local-name="Russian" class="interlanguage-link-target"><span>Русский</span></a></li><li class="interlanguage-link interwiki-sr mw-list-item"><a href="https://sr.wikipedia.org/wiki/%D0%90%D1%81%D1%82%D1%80%D0%BE%D0%BD%D0%BE%D0%BC%D0%B8%D1%98%D1%81%D0%BA%D0%BE_%D0%B1%D1%80%D0%BE%D1%98%D0%B0%D1%9A%D0%B5_%D0%B3%D0%BE%D0%B4%D0%B8%D0%BD%D0%B0" title="Астрономијско бројање година – Serbian" lang="sr" hreflang="sr" data-title="Астрономијско бројање година" data-language-autonym="Српски / srpski" data-language-local-name="Serbian" class="interlanguage-link-target"><span>Српски / srpski</span></a></li><li class="interlanguage-link interwiki-sh mw-list-item"><a href="https://sh.wikipedia.org/wiki/Astronomijsko_brojanje_godina" title="Astronomijsko brojanje godina – Serbo-Croatian" lang="sh" hreflang="sh" data-title="Astronomijsko brojanje godina" data-language-autonym="Srpskohrvatski / српскохрватски" data-language-local-name="Serbo-Croatian" class="interlanguage-link-target"><span>Srpskohrvatski / српскохрватски</span></a></li><li class="interlanguage-link interwiki-tr mw-list-item"><a href="https://tr.wikipedia.org/wiki/Astronomik_y%C4%B1l_numaraland%C4%B1rma" title="Astronomik yıl numaralandırma – Turkish" lang="tr" hreflang="tr" data-title="Astronomik yıl numaralandırma" data-language-autonym="Türkçe" data-language-local-name="Turkish" class="interlanguage-link-target"><span>Türkçe</span></a></li><li class="interlanguage-link interwiki-zh-classical mw-list-item"><a href="https://zh-classical.wikipedia.org/wiki/%E5%A4%A9%E6%96%87%E7%B4%80%E5%B9%B4" title="天文紀年 – Literary Chinese" lang="lzh" hreflang="lzh" data-title="天文紀年" data-language-autonym="文言" data-language-local-name="Literary Chinese" class="interlanguage-link-target"><span>文言</span></a></li><li class="interlanguage-link interwiki-zh mw-list-item"><a href="https://zh.wikipedia.org/wiki/%E5%A4%A9%E6%96%87%E8%A8%88%E5%B9%B4" title="天文計年 – Chinese" lang="zh" hreflang="zh" data-title="天文計年" data-language-autonym="中文" data-language-local-name="Chinese" class="interlanguage-link-target"><span>中文</span></a></li> </ul> <div class="after-portlet after-portlet-lang"><span class="wb-langlinks-edit wb-langlinks-link"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q751976#sitelinks-wikipedia" title="Edit interlanguage links" class="wbc-editpage">Edit links</a></span></div> </div> </div> </div> </header> <div class="vector-page-toolbar"> <div class="vector-page-toolbar-container"> <div id="left-navigation"> <nav aria-label="Namespaces"> <div id="p-associated-pages" class="vector-menu vector-menu-tabs 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class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-appearance.unpin">hide</button> </div> </div> </div> </nav> </div> </div> <div id="bodyContent" class="vector-body" aria-labelledby="firstHeading" data-mw-ve-target-container> <div class="vector-body-before-content"> <div class="mw-indicators"> </div> <div id="siteSub" class="noprint">From Wikipedia, the free encyclopedia</div> </div> <div id="contentSub"><div id="mw-content-subtitle"></div></div> <div id="mw-content-text" class="mw-body-content"><div class="mw-content-ltr mw-parser-output" lang="en" dir="ltr"><div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none">Year numbering system using 0 for 1 BC</div> <p> <b>Astronomical year numbering</b> is based on <a href="/wiki/Anno_Domini" title="Anno Domini">AD</a>/<a href="/wiki/Common_Era" title="Common Era">CE</a> year numbering, but follows normal <a href="/wiki/Decimal" title="Decimal">decimal</a> <a href="/wiki/Integer" title="Integer">integer</a> numbering more strictly. Thus, it has a <a href="/wiki/0_(year)" class="mw-redirect" title="0 (year)">year 0</a>; the years before that are designated with <a href="/wiki/Negative_number" title="Negative number">negative numbers</a> and the years after that are designated with positive numbers.<sup id="cite_ref-nasa-eclipses_1-0" class="reference"><a href="#cite_note-nasa-eclipses-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> Astronomers use the <a href="/wiki/Julian_calendar" title="Julian calendar">Julian calendar</a> for years before 1582, including the year 0, and the <a href="/wiki/Gregorian_calendar" title="Gregorian calendar">Gregorian calendar</a> for years after 1582, as exemplified by <a href="/wiki/Jacques_Cassini" title="Jacques Cassini">Jacques Cassini</a> (1740),<sup id="cite_ref-Cassini_2-0" class="reference"><a href="#cite_note-Cassini-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> <a href="/wiki/Simon_Newcomb" title="Simon Newcomb">Simon Newcomb</a> (1898)<sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> and <a href="/wiki/Fred_Espenak" title="Fred Espenak">Fred Espenak</a> (2007).<sup id="cite_ref-Espanak_4-0" class="reference"><a href="#cite_note-Espanak-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> </p><p>The prefix AD and the suffixes CE, BC or BCE (Common Era, Before Christ or Before Common Era) are dropped.<sup id="cite_ref-nasa-eclipses_1-1" class="reference"><a href="#cite_note-nasa-eclipses-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> The year 1 BC/BCE is numbered 0, the year 2 BC is numbered −1, and in general the year <i>n</i> BC/BCE is numbered "−(<i>n</i> − 1)"<sup id="cite_ref-nasa-eclipses_1-2" class="reference"><a href="#cite_note-nasa-eclipses-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> (a negative number equal to 1 − <i>n</i>). The numbers of AD/CE years are not changed and are written with either no sign or a positive sign; thus in general <i>n</i> AD/CE is simply <i>n</i> or +<i>n</i>.<sup id="cite_ref-nasa-eclipses_1-3" class="reference"><a href="#cite_note-nasa-eclipses-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> For normal calculation a <a href="/wiki/0_(number)" class="mw-redirect" title="0 (number)">number zero</a> is often needed, here most notably when calculating the number of years in a period that spans the <a href="/wiki/Epoch_(astronomy)" title="Epoch (astronomy)">epoch</a>; the end years need only be subtracted from each other. </p><p>The system is so named due to its use in <a href="/wiki/Astronomy" title="Astronomy">astronomy</a>. Few other disciplines outside <a href="/wiki/History" title="History">history</a> deal with the time before year 1, some exceptions being <a href="/wiki/Dendrochronology" title="Dendrochronology">dendrochronology</a>, <a href="/wiki/Archaeology" title="Archaeology">archaeology</a> and <a href="/wiki/Geology" title="Geology">geology</a>, the latter two of which use '<a href="/wiki/Before_Present" title="Before Present">years before the present</a>'. Although the absolute numerical values of astronomical and historical years only differ by one before year 1, this difference is critical when calculating astronomical events like <a href="/wiki/Eclipses" class="mw-redirect" title="Eclipses">eclipses</a> or <a href="/wiki/Planetary_conjunction" class="mw-redirect" title="Planetary conjunction">planetary conjunctions</a> to determine when historical events which mention them occurred. </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Usage_of_the_year_zero">Usage of the year zero</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Astronomical_year_numbering&action=edit&section=1" title="Edit section: Usage of the year zero"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1236090951">.mw-parser-output .hatnote{font-style:italic}.mw-parser-output div.hatnote{padding-left:1.6em;margin-bottom:0.5em}.mw-parser-output .hatnote i{font-style:normal}.mw-parser-output .hatnote+link+.hatnote{margin-top:-0.5em}@media print{body.ns-0 .mw-parser-output .hatnote{display:none!important}}</style><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/Year_zero" title="Year zero">Year zero</a></div> <p>In his <a href="/wiki/Rudolphine_Tables" title="Rudolphine Tables">Rudolphine Tables</a> (1627), <a href="/wiki/Johannes_Kepler" title="Johannes Kepler">Johannes Kepler</a> used a prototype of year zero which he labeled <i>Christi</i> (Christ's) between years labeled <i>Ante Christum</i> (Before Christ) and <i>Post Christum</i> (After Christ) on the mean motion tables for the Sun, Moon, Saturn, Jupiter, Mars, Venus and Mercury.<sup id="cite_ref-5" class="reference"><a href="#cite_note-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> In 1702, the French astronomer <a href="/wiki/Philippe_de_la_Hire" class="mw-redirect" title="Philippe de la Hire">Philippe de la Hire</a> used a year he labeled <span class="nowrap"><i>Christum 0</i></span> at the end of years labeled <i>ante Christum</i> (BC), and immediately before years labeled <i>post Christum</i> (AD) on the mean motion pages in his <i>Tabulæ Astronomicæ</i>, thus adding the designation <i>0</i> to Kepler's <i>Christi</i>.<sup id="cite_ref-6" class="reference"><a href="#cite_note-6"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup> Finally, in 1740 the French astronomer <a href="/wiki/Jacques_Cassini" title="Jacques Cassini">Jacques Cassini</a> <span class="nowrap">(Cassini II)</span>, who is traditionally credited with the invention of year zero,<sup id="cite_ref-7" class="reference"><a href="#cite_note-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-8" class="reference"><a href="#cite_note-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-9" class="reference"><a href="#cite_note-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup> completed the transition in his <i>Tables astronomiques</i>, simply labeling this year <i>0</i>, which he placed at the end of Julian years labeled <i>avant Jesus-Christ</i> (before Jesus Christ or BC), and immediately before Julian years labeled <i>après Jesus-Christ</i> (after Jesus Christ or AD).<sup id="cite_ref-Cassini_2-1" class="reference"><a href="#cite_note-Cassini-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> </p><p>Cassini gave the following reasons for using a year 0:<sup id="cite_ref-10" class="reference"><a href="#cite_note-10"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup> </p> <style data-mw-deduplicate="TemplateStyles:r1244412712">.mw-parser-output .templatequote{overflow:hidden;margin:1em 0;padding:0 32px}.mw-parser-output .templatequotecite{line-height:1.5em;text-align:left;margin-top:0}@media(min-width:500px){.mw-parser-output .templatequotecite{padding-left:1.6em}}</style><blockquote class="templatequote"><p>The year 0 is that in which one supposes that Jesus Christ was born, which several chronologists mark 1 before the birth of Jesus Christ and which we marked 0, so that the sum of the years before and after Jesus Christ gives the interval which is between these years, and where numbers divisible by 4 mark the leap years as so many before or after Jesus Christ.</p><div class="templatequotecite">— <cite>Jacques Cassini</cite></div></blockquote> <p>Fred Espenak of <a href="/wiki/NASA" title="NASA">NASA</a> lists 50 <a href="/wiki/Lunar_phase" title="Lunar phase">phases of the Moon</a> within year 0, showing that it is a full year, not an instant in time.<sup id="cite_ref-Espanak_4-1" class="reference"><a href="#cite_note-Espanak-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> Jean Meeus gives the following explanation:<sup id="cite_ref-11" class="reference"><a href="#cite_note-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> </p> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1244412712"><blockquote class="templatequote"><p>There is a disagreement between astronomers and historians about how to count the years preceding year 1. In [<i>Astronomical Algorithms</i>], the 'B.C.' years are counted astronomically. Thus, the year before the year +1 is the year zero, and the year preceding the latter is the year −1. The year which historians call 585 B.C. is actually the year −584. The astronomical counting of the negative years is the only one suitable for arithmetical purpose. For example, in the historical practice of counting, the rule of divisibility by 4 revealing Julian leap-years no longer exists; these years are, indeed, 1, 5, 9, 13, ... B.C. In the astronomical sequence, however, these leap-years are called 0, −4, −8, −12, ..., and the rule of divisibility by 4 subsists.</p><div class="templatequotecite">— <cite>Jean Meeus, <i>Astronomical Algorithms</i></cite></div></blockquote> <div class="mw-heading mw-heading2"><h2 id="Signed_years_without_the_year_zero">Signed years without the year zero</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Astronomical_year_numbering&action=edit&section=2" title="Edit section: Signed years without the year zero"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Although he used the usual French terms "avant J.-C." (before Jesus Christ) and "après J.-C." (after Jesus Christ) to label years elsewhere in his book, the Byzantine historian <a href="/wiki/Venance_Grumel" title="Venance Grumel">Venance Grumel</a> (1890–1967) used negative years (identified by a minus sign, −) to label BC years and unsigned positive years to label AD years in a table. He may have done so to save space and he put no year 0 between them.<sup id="cite_ref-12" class="reference"><a href="#cite_note-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup> </p><p>Version 1.0 of the <a href="/wiki/XML_Schema_(W3C)" title="XML Schema (W3C)">XML Schema language</a>, often used to describe data interchanged between computers in <a href="/wiki/XML" title="XML">XML</a>, includes built-in primitive datatypes <b>date</b> and <b>dateTime</b>. Although these are defined in terms of <a href="/wiki/ISO_8601" title="ISO 8601">ISO 8601</a> which uses the <a href="/wiki/Proleptic_Gregorian_calendar" title="Proleptic Gregorian calendar">proleptic Gregorian calendar</a> and therefore should include a year 0, the XML Schema specification states that there is no year zero. Version 1.1 of the defining <a href="/wiki/W3C_recommendation" class="mw-redirect" title="W3C recommendation">recommendation</a> realigned the specification with ISO 8601 by including a year zero, despite the problems arising from the lack of <a href="/wiki/Backward_compatibility" title="Backward compatibility">backward compatibility</a>.<sup id="cite_ref-13" class="reference"><a href="#cite_note-13"><span class="cite-bracket">[</span>13<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="See_also">See also</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Astronomical_year_numbering&action=edit&section=3" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/Julian_day" title="Julian day">Julian day</a>, another calendar commonly used by astronomers</li> <li><a href="/wiki/Astronomical_chronology" title="Astronomical chronology">Astronomical chronology</a></li> <li><a href="/wiki/Holocene_calendar" title="Holocene calendar">Holocene calendar</a></li> <li><a href="/wiki/ISO_8601" title="ISO 8601">ISO 8601</a></li></ul> <div class="mw-heading mw-heading2"><h2 id="References">References</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Astronomical_year_numbering&action=edit&section=4" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist reflist-columns references-column-width" style="column-width: 30em;"> <ol class="references"> <li id="cite_note-nasa-eclipses-1"><span class="mw-cite-backlink">^ <a href="#cite_ref-nasa-eclipses_1-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-nasa-eclipses_1-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-nasa-eclipses_1-2"><sup><i><b>c</b></i></sup></a> <a href="#cite_ref-nasa-eclipses_1-3"><sup><i><b>d</b></i></sup></a></span> <span class="reference-text"><style data-mw-deduplicate="TemplateStyles:r1238218222">.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output .cs1-format{font-size:95%}html.skin-theme-clientpref-night .mw-parser-output .cs1-maint{color:#18911f}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .cs1-maint{color:#18911f}}</style><cite id="CITEREFEspenak" class="citation web cs1">Espenak, Fred. <a rel="nofollow" class="external text" href="https://eclipse.gsfc.nasa.gov/SEhelp/dates.html">"Year Dating Conventions"</a>. <i>NASA Eclipse Web Site</i>. NASA. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20090208212742/http://eclipse.gsfc.nasa.gov/SEhelp/dates.html">Archived</a> from the original on 8 February 2009<span class="reference-accessdate">. Retrieved <span class="nowrap">19 February</span> 2009</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=NASA+Eclipse+Web+Site&rft.atitle=Year+Dating+Conventions&rft.aulast=Espenak&rft.aufirst=Fred&rft_id=http%3A%2F%2Feclipse.gsfc.nasa.gov%2FSEhelp%2Fdates.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AAstronomical+year+numbering" class="Z3988"></span></span> </li> <li id="cite_note-Cassini-2"><span class="mw-cite-backlink">^ <a href="#cite_ref-Cassini_2-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Cassini_2-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text">Jacques Cassini, <i><a rel="nofollow" class="external text" href="https://books.google.com/books?id=fVIVAAAAQAAJ&pg=RA1-PA10">Tables Astronomiques</a></i> (1740), Explication et Usage pp. 5 (PA5), 7 (PA7), Tables pp. 10 (RA1-PA10), 22 (RA1-PA22), 63 (RA1-PA63), 77 (RA1-PA77), 91 (RA1-PA91), 105 (RA1-PA105), 119 (RA1-PA119). <span class="languageicon">(in French)</span></span> </li> <li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text">Simon Newcomb, <a rel="nofollow" class="external text" href="https://archive.org/details/06AstronomicalPapersPreparedForTheUse">"Tables of the Motion of the Earth on its Axis and Around the Sun"</a> in <i>Astronomical Papers Prepared for the Use of the American Ephemeris and Nautical Almanac, Volume VI: Tables of the Four Inner Planets</i>, (United States Naval Observatory, 1898), pp. 27 & 34–35.</span> </li> <li id="cite_note-Espanak-4"><span class="mw-cite-backlink">^ <a href="#cite_ref-Espanak_4-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Espanak_4-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text">Fred Espenak, <a rel="nofollow" class="external text" href="https://eclipse.gsfc.nasa.gov/phase/phases-0099.html">Phases of the Moon: −99 to 0 (100 to 1 BCE)</a> <a rel="nofollow" class="external text" href="https://web.archive.org/web/20090605101653/http://eclipse.gsfc.nasa.gov/phase/phases-0099.html">Archived</a> 5 June 2009 at the <a href="/wiki/Wayback_Machine" title="Wayback Machine">Wayback Machine</a> <i>NASA Eclipse web site</i></span> </li> <li id="cite_note-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-5">^</a></b></span> <span class="reference-text">Johannes Kepler, <i><a rel="nofollow" class="external text" href="http://www.ub.uni-kiel.de/digiport/bis1800/Arch3_436.html">Tabulae Rudolphinae</a></i> (1627) Pars secunda, 42 (Zu Seite 191), 48 (197), 54 (203), 60 (209), 66 (215), 72 (221), 78 (227). (Latin)</span> </li> <li id="cite_note-6"><span class="mw-cite-backlink"><b><a href="#cite_ref-6">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="https://books.google.com/books?id=BjygAAAAMAAJ">Tabulae Astronomicae – Philippo de la Hire</a> (1702), Tabulæ 15, 21, 39, 47, 55, 63, 71; Usus tabularum 4. (Latin)</span> </li> <li id="cite_note-7"><span class="mw-cite-backlink"><b><a href="#cite_ref-7">^</a></b></span> <span class="reference-text">Robert Kaplan, <a rel="nofollow" class="external text" href="https://books.google.com/books?id=Bn0EBVsfi1YC&pg=PA103"><i>The nothing that is</i></a> (Oxford: Oxford University Press, 2000) 103.</span> </li> <li id="cite_note-8"><span class="mw-cite-backlink"><b><a href="#cite_ref-8">^</a></b></span> <span class="reference-text">Dick Teresi, <a rel="nofollow" class="external text" href="https://www.theatlantic.com/past/docs/issues/97jul/zero.htm">"Zero"</a>, <i>The Atlantic</i>, July 1997 (see under Calendars and the Cosmos).</span> </li> <li id="cite_note-9"><span class="mw-cite-backlink"><b><a href="#cite_ref-9">^</a></b></span> <span class="reference-text">L. E. Doggett, <a rel="nofollow" class="external text" href="http://charon.nmsu.edu/~lhuber/leaphist.html">"Calendars"</a> <a rel="nofollow" class="external text" href="https://web.archive.org/web/20120210184836/http://charon.nmsu.edu/~lhuber/leaphist.html">Archived</a> 10 February 2012 at the <a href="/wiki/Wayback_Machine" title="Wayback Machine">Wayback Machine</a>, <i>Explanatory Supplement to the Astronomical Almanac</i>, ed. P. Kenneth Seidelmann, (Sausalito, California: University Science Books, 1992/2005) 579.</span> </li> <li id="cite_note-10"><span class="mw-cite-backlink"><b><a href="#cite_ref-10">^</a></b></span> <span class="reference-text">Jacques Cassini, <i><a rel="nofollow" class="external text" href="https://books.google.com/books?id=fVIVAAAAQAAJ&pg=RA1-PA3">Tables astronomiques</a></i>, 1740, Explication et Usage p. 5, translated by Wikipedia from the French:<br /> "L'année 0 est celle dans laquelle on suppose qu'est né Jesus-Christ & que plusieurs Chronologistes marquent 1 avant la naissance de J. C. & que nous avons marquée 0, afin que la somme des années avant & après J. C. donne l'intervalle qui est entre ces années, & que les nombres divisibles par 4 marquent les années bissextiles tant avant qu'après Jesus-Christ."</span> </li> <li id="cite_note-11"><span class="mw-cite-backlink"><b><a href="#cite_ref-11">^</a></b></span> <span class="reference-text">Jean Meeus, <i>Astronomical Algorithms</i> (Richmond, Virginia: Willmann-Bell, 1991) 60.</span> </li> <li id="cite_note-12"><span class="mw-cite-backlink"><b><a href="#cite_ref-12">^</a></b></span> <span class="reference-text">V. Grumel, <i>La chronologie</i> (Paris: Presses Universitaires de France, 1958) 30. <span class="languageicon">(in French)</span></span> </li> <li id="cite_note-13"><span class="mw-cite-backlink"><b><a href="#cite_ref-13">^</a></b></span> <span class="reference-text">Biron, P.V. & Malhotra, A. (Eds.). (28 October 2004). <a rel="nofollow" class="external text" href="http://www.w3.org/TR/xmlschema-2/#dateTime"><i>XML Schema Part 2: Datatypes</i> (2nd ed.).</a> World Wide Web Consortium.</span> </li> </ol></div> <div class="navbox-styles"><style data-mw-deduplicate="TemplateStyles:r1129693374">.mw-parser-output .hlist dl,.mw-parser-output .hlist ol,.mw-parser-output .hlist ul{margin:0;padding:0}.mw-parser-output .hlist dd,.mw-parser-output .hlist dt,.mw-parser-output .hlist li{margin:0;display:inline}.mw-parser-output .hlist.inline,.mw-parser-output .hlist.inline dl,.mw-parser-output .hlist.inline ol,.mw-parser-output .hlist.inline ul,.mw-parser-output .hlist dl dl,.mw-parser-output .hlist dl ol,.mw-parser-output .hlist dl ul,.mw-parser-output .hlist ol dl,.mw-parser-output .hlist ol ol,.mw-parser-output .hlist ol ul,.mw-parser-output .hlist ul dl,.mw-parser-output .hlist ul ol,.mw-parser-output .hlist ul ul{display:inline}.mw-parser-output .hlist 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href="/wiki/Calendar" title="Calendar">Calendars</a></div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%">Systems</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Lunar_calendar" title="Lunar calendar">Lunar</a></li> <li><a href="/wiki/Lunisolar_calendar" title="Lunisolar calendar">Lunisolar</a></li> <li><a href="/wiki/Solar_calendar" title="Solar calendar">Solar</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">In wide use</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a class="mw-selflink selflink">Astronomical</a></li> <li><a href="/wiki/Buddhist_calendar" title="Buddhist calendar">Buddhist</a></li> <li><a href="/wiki/Chinese_calendar" title="Chinese calendar">Chinese</a></li> <li><a href="/wiki/Ethiopian_calendar" title="Ethiopian calendar">Ethiopian</a></li> <li><a href="/wiki/Gregorian_calendar" title="Gregorian calendar">Gregorian</a></li> <li><a href="/wiki/Hindu_calendar" title="Hindu calendar">Hindu</a></li> <li><a href="/wiki/Islamic_calendar" title="Islamic calendar">Lunar Hijri</a></li> <li><a href="/wiki/Solar_Hijri_calendar" title="Solar Hijri calendar">Solar Hijri</a></li> <li><a href="/wiki/ISO_week_date" title="ISO week date">ISO</a></li> <li><a href="/wiki/Unix_time" title="Unix time">Unix time</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><div style="display: inline-block; line-height: 1.2em; padding: .1em 0;">In more<br />limited use</div></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><td colspan="2" class="navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Akan_calendar" title="Akan calendar">Akan</a></li> <li><a href="/wiki/Armenian_calendar" title="Armenian calendar">Armenian</a></li> <li><a href="/wiki/Assamese_calendar" title="Assamese calendar">Assamese (Bhāshkarābda)</a></li> <li><a href="/wiki/Assyrian_calendar" title="Assyrian calendar">Assyrian</a></li> <li><a href="/wiki/Bah%C3%A1%CA%BC%C3%AD_calendar" title="Baháʼí calendar">Baháʼí</a> <ul><li>Badí‘</li></ul></li> <li>Bali <ul><li><a href="/wiki/Pawukon_calendar" title="Pawukon calendar">Pawukon</a></li> <li><a href="/wiki/Balinese_saka_calendar" title="Balinese saka calendar">Saka</a></li></ul></li> <li><a href="/wiki/Bengali_calendars" title="Bengali calendars">Bengali</a> <ul><li><a href="/wiki/Bangladeshi_calendar" class="mw-redirect" title="Bangladeshi calendar">Bangladeshi</a></li></ul></li> <li><a href="/wiki/Berber_calendar" title="Berber calendar">Berber</a></li> <li><a href="/wiki/Borana_calendar" title="Borana calendar">Borana</a></li> <li><a href="/wiki/Burmese_calendar" title="Burmese calendar">Burmese</a></li> <li><a href="/wiki/Chinese_calendar" title="Chinese calendar">Chinese</a> <ul><li><a href="/wiki/Earthly_Branches" title="Earthly Branches">Earthly Branches</a></li> <li><a href="/wiki/Heavenly_Stems" title="Heavenly Stems">Heavenly Stems</a></li> <li><a href="/wiki/Republic_of_China_calendar" title="Republic of China calendar">Minguo</a></li> <li><a href="/wiki/Solar_term" title="Solar term">Solar term</a></li></ul></li> <li><a href="/wiki/Heathen_holidays" title="Heathen holidays">Germanic heathen</a></li> <li><a href="/wiki/Georgian_calendar" title="Georgian calendar">Georgian</a></li> <li><a href="/wiki/Hebrew_calendar" title="Hebrew calendar">Hebrew</a></li> <li><a href="/wiki/Hindu_calendar" title="Hindu calendar">Hindu</a> <ul><li><a href="/wiki/Vikram_Samvat" title="Vikram Samvat">Vikram Samvat</a></li> <li><a href="/wiki/Indian_national_calendar" title="Indian national calendar">Saka</a></li></ul></li> <li><a href="/wiki/Hmong_calendar" title="Hmong calendar">Hmong</a></li> <li><a href="/wiki/Igbo_calendar" title="Igbo calendar">Igbo</a></li> <li><a href="/wiki/Iranian_calendars" title="Iranian calendars">Iranian</a> <ul><li><a href="/wiki/Jalali_calendar" title="Jalali calendar">Jalali</a> <ul><li>medieval</li></ul></li> <li><a href="/wiki/Zoroastrian_calendar" title="Zoroastrian calendar">Zoroastrian</a></li></ul></li> <li><a href="/wiki/Irish_calendar" title="Irish calendar">Irish</a> <ul><li>Gaelic</li></ul></li> <li><a href="/wiki/Islamic_calendar" title="Islamic calendar">Islamic</a> <ul><li><a href="/wiki/Fasli_calendar" title="Fasli calendar">Fasli</a></li> <li><a href="/wiki/Tabular_Islamic_calendar" title="Tabular Islamic calendar">Tabular</a></li></ul></li> <li><a href="/wiki/Vira_Nirvana_Samvat" title="Vira Nirvana Samvat">Jain</a></li> <li><a href="/wiki/Japanese_calendar" title="Japanese calendar">Japanese</a></li> <li><a href="/wiki/Javanese_calendar" title="Javanese calendar">Javanese</a></li> <li><a href="/wiki/Korean_calendar" title="Korean calendar">Korean</a> <ul><li><a href="/wiki/Juche_calendar" title="Juche calendar">Juche</a></li></ul></li> <li><a href="/wiki/Kurdish_calendar" title="Kurdish calendar">Kurdish</a></li> <li><a href="/wiki/Lithuanian_calendar" title="Lithuanian calendar">Lithuanian</a></li> <li><a href="/wiki/Tirhuta_Panchang" title="Tirhuta Panchang">Maithili</a></li> <li><a href="/wiki/Malayalam_calendar" title="Malayalam calendar">Malayalam</a></li> <li><a href="/wiki/Mandaean_calendar" title="Mandaean calendar">Mandaean</a></li> <li><a href="/wiki/Meitei_calendar" title="Meitei calendar">Manipuri (Meitei)</a></li> <li><a href="/wiki/Melanau_calendar" title="Melanau calendar">Melanau</a></li> <li><a href="/wiki/Mongolian_calendar" title="Mongolian calendar">Mongolian</a></li> <li>Nepal <ul><li><a href="/wiki/Nepal_Sambat" title="Nepal Sambat">Nepal Sambat</a></li> <li><a href="/wiki/Vikram_Samvat" title="Vikram Samvat">Vikram Samvat</a></li> <li><a href="/wiki/Yele_Sambat" title="Yele Sambat">Yele Sambat</a></li></ul></li> <li><a href="/wiki/Nisga%27a#Nisga’a_calendar/life" title="Nisga'a">Nisg̱a'a</a></li> <li><a href="/wiki/Odia_calendar" title="Odia calendar">Odia</a></li> <li><a href="/wiki/Punjabi_calendar" title="Punjabi calendar">Punjabi</a> <ul><li><a href="/wiki/Nanakshahi_calendar" title="Nanakshahi calendar">Nanakshahi</a></li></ul></li> <li><a href="/wiki/Romanian_calendar" title="Romanian calendar">Romanian</a></li> <li><a href="/wiki/Shona_calendar" title="Shona calendar">Shona</a></li> <li><a href="/wiki/Somali_calendar" title="Somali calendar">Somali</a></li> <li><a href="/wiki/Sotho_calendar" title="Sotho calendar">Sesotho</a></li> <li><a href="/wiki/Slavic_calendar" title="Slavic calendar">Slavic</a> <ul><li><a href="/wiki/Slavic_Native_Faith%27s_calendars_and_holidays" title="Slavic Native Faith's calendars and holidays">Slavic Native Faith</a></li> <li><a href="/wiki/Macedonian_months" title="Macedonian months">Macedonian</a></li></ul></li> <li><a href="/wiki/Tamil_calendar" title="Tamil calendar">Tamil</a></li> <li><a href="/wiki/Thai_calendar" title="Thai calendar">Thai</a> <ul><li><a href="/wiki/Thai_lunar_calendar" title="Thai lunar calendar">lunar</a></li> <li><a href="/wiki/Thai_solar_calendar" title="Thai solar calendar">solar</a></li></ul></li> <li><a href="/wiki/Tibetan_calendar" title="Tibetan calendar">Tibetan</a></li> <li><a href="/wiki/Tripuri_calendar" title="Tripuri calendar">Tripuri</a></li> <li><a href="/wiki/Tulu_calendar" title="Tulu calendar">Tulu</a></li> <li><a href="/wiki/Vietnamese_calendar" title="Vietnamese calendar">Vietnamese</a></li> <li><a href="/wiki/Wheel_of_the_Year" title="Wheel of the Year">Wicca</a></li> <li><a href="/wiki/Xhosa_calendar" title="Xhosa calendar">Xhosa</a></li> <li><a href="/wiki/Yoruba_calendar" title="Yoruba calendar">Yoruba</a></li> <li><a href="/wiki/Zulu_calendar" title="Zulu calendar">Zulu</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;font-weight:normal;">Types</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Runic_calendar" title="Runic calendar">Runic</a></li> <li><a href="/wiki/Mesoamerican_calendars" title="Mesoamerican calendars">Mesoamerican</a> <ul><li><a href="/wiki/Mesoamerican_Long_Count_calendar" title="Mesoamerican Long Count calendar">Long Count</a></li> <li><a href="/wiki/Calendar_round" class="mw-redirect" title="Calendar round">Calendar round</a></li></ul></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;font-weight:normal;">Christian variants</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Coptic_calendar" title="Coptic calendar">Coptic</a></li> <li><a href="/wiki/Ethiopian_calendar" title="Ethiopian calendar">Ethiopian and Eritrean</a></li> <li><a href="/wiki/Julian_calendar" title="Julian calendar">Julian</a> <ul><li><a href="/wiki/Revised_Julian_calendar" title="Revised Julian calendar">Revised</a></li></ul></li> <li><a href="/wiki/Liturgical_year" title="Liturgical year">Liturgical year</a> <ul><li><a href="/wiki/Eastern_Orthodox_liturgical_calendar" title="Eastern Orthodox liturgical calendar">Eastern Orthodox</a></li></ul></li> <li><a href="/wiki/Calendar_of_saints" title="Calendar of saints">Saints</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Historical</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Pre-Islamic_Arabian_calendar" title="Pre-Islamic Arabian calendar">Arabian</a></li> <li><a href="/wiki/Attic_calendar" title="Attic calendar">Attic</a></li> <li><a href="/wiki/Aztec_calendar" title="Aztec calendar">Aztec</a> <ul><li><a href="/wiki/T%C5%8Dnalp%C5%8Dhualli" title="Tōnalpōhualli">Tōnalpōhualli</a></li> <li><a href="/wiki/Xiuhp%C5%8Dhualli" title="Xiuhpōhualli">Xiuhpōhualli</a></li></ul></li> <li><a href="/wiki/Babylonian_calendar" title="Babylonian calendar">Babylonian</a></li> <li><a href="/wiki/Bulgar_calendar" title="Bulgar calendar">Bulgar</a></li> <li><a href="/wiki/Byzantine_calendar" title="Byzantine calendar">Byzantine</a></li> <li><a href="/wiki/Cappadocian_calendar" title="Cappadocian calendar">Cappadocian</a></li> <li><a href="/wiki/Celtic_calendar" title="Celtic calendar">Celtic</a></li> <li><a href="/wiki/Cham_calendar" title="Cham calendar">Cham</a></li> <li><a href="/wiki/Chula_Sakarat" title="Chula Sakarat">Culāsakaraj</a></li> <li><a href="/wiki/Coligny_calendar" title="Coligny calendar">Coligny</a></li> <li><a href="/wiki/Egyptian_calendar" title="Egyptian calendar">Egyptian</a></li> <li><a href="/wiki/Enoch_calendar" title="Enoch calendar">Enoch</a></li> <li><a href="/wiki/Florentine_calendar" title="Florentine calendar">Florentine</a></li> <li><a href="/wiki/French_Republican_calendar" title="French Republican calendar">French Republican</a></li> <li><a href="/wiki/Germanic_calendar" class="mw-redirect" title="Germanic calendar">Germanic</a></li> <li><a href="/wiki/Ancient_Greek_calendars" title="Ancient Greek calendars">Greek</a></li> <li><a href="/wiki/Hindu_calendar" title="Hindu calendar">Hindu</a></li> <li><a href="/wiki/Inca_calendar" class="mw-redirect" title="Inca calendar">Inca</a></li> <li><a href="/wiki/Ancient_Macedonian_calendar" title="Ancient Macedonian calendar">Macedonian</a></li> <li><a href="/wiki/Maya_calendar" title="Maya calendar">Maya</a> <ul><li><a href="/wiki/Haab%CA%BC" title="Haabʼ">Haabʼ</a></li> <li><a href="/wiki/Tzolk%CA%BCin" title="Tzolkʼin">Tzolkʼin</a></li></ul></li> <li><a href="/wiki/Muisca_calendar" title="Muisca calendar">Muisca</a></li> <li><a href="/wiki/Pentecontad_calendar" title="Pentecontad calendar">Pentecontad</a></li> <li><a href="/wiki/Pisan_calendar" title="Pisan calendar">Pisan</a></li> <li><a href="/wiki/Qumran_calendrical_texts" title="Qumran calendrical texts">Qumran</a></li> <li><a href="/wiki/Rapa_Nui_calendar" title="Rapa Nui calendar">Rapa Nui</a></li> <li><a href="/wiki/Roman_calendar" title="Roman calendar">Roman</a></li> <li><a href="/wiki/Rumi_calendar" title="Rumi calendar"><i>Rumi</i></a></li> <li><a href="/wiki/Sexagenary_cycle" title="Sexagenary cycle">Sexagenary</a></li> <li><a href="/wiki/Soviet_calendar" title="Soviet calendar">Soviet</a></li> <li><a href="/wiki/Swedish_calendar" title="Swedish calendar">Swedish</a></li> <li><a href="/wiki/2002_renaming_of_Turkmen_months_and_days_of_week" title="2002 renaming of Turkmen months and days of week">Turkmen</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">By specialty</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Holocene_calendar" title="Holocene calendar">Holocene</a> <ul><li>anthropological</li></ul></li> <li><a href="/wiki/Proleptic_Gregorian_calendar" title="Proleptic Gregorian calendar">Proleptic Gregorian</a> / <a href="/wiki/Proleptic_Julian_calendar" title="Proleptic Julian calendar">Proleptic Julian</a> <ul><li>historiographical</li></ul></li> <li><a href="/wiki/Darian_calendar" title="Darian calendar">Darian</a> <ul><li>Martian</li></ul></li> <li><a href="/wiki/Dreamspell" title="Dreamspell">Dreamspell</a> <ul><li>New Age</li></ul></li> <li><a href="/wiki/Discordian_calendar" title="Discordian calendar">Discordian</a></li> <li><a href="/wiki/%27Pataphysics#Pataphysical_calendar" title="'Pataphysics">'Pataphysical</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Calendar_reform" title="Calendar reform">Reform proposals</a></th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Hanke%E2%80%93Henry_Permanent_Calendar" title="Hanke–Henry Permanent Calendar">Hanke–Henry Permanent</a></li> <li><a href="/wiki/International_Fixed_Calendar" title="International Fixed Calendar">International Fixed</a></li> <li><a href="/wiki/Pax_Calendar" title="Pax Calendar">Pax</a></li> <li><a href="/wiki/Positivist_calendar" title="Positivist calendar">Positivist</a></li> <li><a href="/wiki/Symmetry454" title="Symmetry454">Symmetry454</a></li> <li><a href="/wiki/World_Calendar" title="World Calendar">World</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><div style="display: inline-block; line-height: 1.2em; padding: .1em 0;">Displays and<br />applications</div></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Calendaring_software" class="mw-redirect" title="Calendaring software">Electronic</a></li> <li><a href="/wiki/Perpetual_calendar" title="Perpetual calendar">Perpetual</a></li> <li><a href="/wiki/Calendar_(stationery)" title="Calendar (stationery)">Wall</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><div style="display: inline-block; line-height: 1.2em; padding: .1em 0;">Year naming<br />and numbering</div></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%;font-weight:normal;">Terminology</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Calendar_era" title="Calendar era">Era</a></li> <li><a href="/wiki/Epoch" title="Epoch">Epoch</a></li> <li><a href="/wiki/Leap_year" title="Leap year">Leap year</a></li> <li><a href="/wiki/New_Year" title="New Year">New Year</a></li> <li><a href="/wiki/Regnal_name" title="Regnal name">Regnal name</a></li> <li><a href="/wiki/Regnal_year" title="Regnal year">Regnal year</a></li> <li><a href="/wiki/Year_zero" title="Year zero">Year zero</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;font-weight:normal;">Systems</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Ab_urbe_condita" title="Ab urbe condita">Ab urbe condita</a></li> <li><a href="/wiki/Anka_year" title="Anka year">Anka year</a></li> <li><a href="/wiki/Anno_Domini" title="Anno Domini">Anno Domini</a>/<a href="/wiki/Common_Era" title="Common Era">Common Era</a></li> <li><a href="/wiki/Anno_Lucis" title="Anno Lucis">Anno Lucis</a></li> <li><a href="/wiki/Era_of_the_Martyrs" title="Era of the Martyrs">Anno Martyrum</a></li> <li><a href="/wiki/Anno_Mundi" title="Anno Mundi">Anno Mundi</a></li> <li><a href="/wiki/Eponym_dating_system" title="Eponym dating system">Assyrian</a></li> <li><a href="/wiki/Before_Present" title="Before Present">Before Present</a></li> <li><a href="/wiki/Chinese_era_name" title="Chinese era name">Chinese Imperial</a></li> <li><a href="/wiki/Republic_of_China_calendar" title="Republic of China calendar">Chinese Minguo</a></li> <li><a href="/wiki/Regnal_years_of_English_and_British_monarchs" title="Regnal years of English and British monarchs">English and British regnal year</a></li> <li><a href="/wiki/Hijri_year" title="Hijri year">Hijri year</a></li> <li><a href="/wiki/Holocene_calendar" title="Holocene calendar">Human (Holocene)</a></li> <li><a href="/wiki/Japanese_era_name" title="Japanese era name">Japanese</a></li> <li><a href="/wiki/Korean_era_name" title="Korean era name">Korean</a></li> <li><a href="/wiki/Nirayana_system" title="Nirayana system">Nirayana system</a></li> <li><a href="/wiki/Seleucid_era" title="Seleucid era">Seleucid</a></li> <li><a href="/wiki/Spanish_era" title="Spanish era">Spanish</a></li> <li><a href="/wiki/Yuga" title="Yuga">Yugas</a> <ul><li><a href="/wiki/Satya_Yuga" title="Satya Yuga">Satya</a></li> <li><a href="/wiki/Treta_Yuga" title="Treta Yuga">Treta</a></li> <li><a href="/wiki/Dvapara_Yuga" title="Dvapara Yuga">Dvapara</a></li> <li><a href="/wiki/Kali_Yuga" title="Kali Yuga">Kali</a></li></ul></li> <li><a href="/wiki/Vietnamese_era_name" title="Vietnamese era name">Vietnamese</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Fictional</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Discworld_(world)#Calendar" title="Discworld (world)">Discworld</a> (<i><a href="/wiki/Discworld" title="Discworld">Discworld</a></i>)</li> <li><a href="/wiki/Flanaess#Calendar" class="mw-redirect" title="Flanaess">Greyhawk</a> (<i><a href="/wiki/Dungeons_%26_Dragons" title="Dungeons & Dragons">Dungeons & Dragons</a></i>)</li> <li><a href="/wiki/Middle-earth_calendar" class="mw-redirect" title="Middle-earth calendar">Middle-earth</a> (<i><a href="/wiki/The_Lord_of_the_Rings" title="The Lord of the Rings">The Lord of the Rings</a></i>)</li> <li><a href="/wiki/Stardate" title="Stardate">Stardate</a> (<i><a href="/wiki/Star_Trek" title="Star Trek">Star Trek</a></i>)</li></ul> </div></td></tr><tr><td class="navbox-abovebelow hlist" colspan="2"><div> <ul><li><span class="noviewer" typeof="mw:File"><span title="List-Class article"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/d/db/Symbol_list_class.svg/16px-Symbol_list_class.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/d/db/Symbol_list_class.svg/23px-Symbol_list_class.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/d/db/Symbol_list_class.svg/31px-Symbol_list_class.svg.png 2x" data-file-width="180" data-file-height="185" /></span></span> <a href="/wiki/List_of_calendars" title="List of calendars">List of calendars</a></li> <li><span class="noviewer" typeof="mw:File"><span title="Category"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/16px-Symbol_category_class.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/23px-Symbol_category_class.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/31px-Symbol_category_class.svg.png 2x" data-file-width="180" data-file-height="185" /></span></span> <a href="/wiki/Category:Calendars" title="Category:Calendars">Category</a></li></ul> </div></td></tr></tbody></table></div> <div class="navbox-styles"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236075235"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"></div><div role="navigation" class="navbox" aria-labelledby="Chronology" style="padding:3px"><table class="nowraplinks mw-collapsible mw-collapsed navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239400231"><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Chronology" title="Template:Chronology"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Chronology" title="Template talk:Chronology"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Chronology" title="Special:EditPage/Template:Chronology"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Chronology" style="font-size:114%;margin:0 4em"><a href="/wiki/Chronology" title="Chronology">Chronology</a></div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%;line-height:1.2em;background:#cc9;">Key topics</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Archaeology" title="Archaeology">Archaeology</a></li> <li><a href="/wiki/Astronomy" title="Astronomy">Astronomy</a></li> <li><a href="/wiki/Geology" title="Geology">Geology</a></li> <li><a href="/wiki/History" title="History">History</a> <ul><li><a href="/wiki/Big_History" title="Big History">Big History</a></li></ul></li> <li><a href="/wiki/Paleontology" title="Paleontology">Paleontology</a></li> <li><a href="/wiki/Time" title="Time">Time</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;line-height:1.2em;background:#cc9;"><div class="hlist"><ul><li><a href="/wiki/Periodization" title="Periodization">Periods</a></li><li><a href="/wiki/Era" title="Era">Eras</a></li><li><a href="/wiki/Epoch_(reference_date)" class="mw-redirect" title="Epoch (reference date)">Epochs</a></li></ul></div></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:8.0em;font-weight:normal;background:#cc9;"><a href="/wiki/Calendar_era" title="Calendar era">Calendar eras</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Holocene_calendar" title="Holocene calendar">Human Era</a></li> <li><i><a href="/wiki/Ab_urbe_condita" title="Ab urbe condita">Ab urbe condita</a></i></li> <li><a href="/wiki/Anno_Domini" title="Anno Domini">Anno Domini</a> / <a href="/wiki/Common_Era" title="Common Era">Common Era</a></li> <li><a href="/wiki/Anno_Mundi" title="Anno Mundi">Anno Mundi</a></li> <li><a href="/wiki/Bosporan_era" title="Bosporan era">Bosporan era</a></li> <li><a href="/wiki/Bostran_era" title="Bostran era">Bostran era</a></li> <li><a href="/wiki/Byzantine_calendar" title="Byzantine calendar">Byzantine era</a></li> <li><a href="/wiki/Seleucid_era" title="Seleucid era">Seleucid era</a></li> <li><a href="/wiki/Era_of_Caesar_(Iberian_Peninsula)" class="mw-redirect" title="Era of Caesar (Iberian Peninsula)">Era of Caesar (Iberia)</a></li> <li><a href="/wiki/Before_present" class="mw-redirect" title="Before present">Before present</a></li> <li><a href="/wiki/Islamic_calendar" title="Islamic calendar">Hijri</a></li> <li><a href="/wiki/Egyptian_chronology" title="Egyptian chronology">Egyptian</a></li> <li><a href="/wiki/Sothic_cycle" title="Sothic cycle">Sothic cycle</a></li> <li><a href="/wiki/Hindu_units_of_time" title="Hindu units of time">Hindu units of time</a> (<a href="/wiki/Yuga" title="Yuga">Yuga</a>)</li> <li><a href="/wiki/Mesoamerican_calendars" title="Mesoamerican calendars">Mesoamerican</a> <ul><li><a href="/wiki/Mesoamerican_Long_Count_calendar" title="Mesoamerican Long Count calendar">Long Count</a></li> <li><a href="/wiki/Maya_calendar#Short_Count" title="Maya calendar">Short Count</a></li> <li><a href="/wiki/Tzolk%27in" class="mw-redirect" title="Tzolk'in">Tzolk'in</a></li> <li><a href="/wiki/Haab%27" class="mw-redirect" title="Haab'">Haab'</a></li></ul></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:8.0em;font-weight:normal;background:#cc9;"><a href="/wiki/Regnal_year" title="Regnal year">Regnal year</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Anka_year" title="Anka year">Anka year</a></li> <li><a href="/wiki/Canon_of_Kings" title="Canon of Kings">Canon of Kings</a></li> <li><a href="/wiki/Regnal_years_of_English_and_British_monarchs" title="Regnal years of English and British monarchs">English and British regnal year</a></li> <li><a href="/wiki/Category:Regnal_lists" title="Category:Regnal lists">Lists of kings</a></li> <li><a href="/wiki/Limmu" title="Limmu">Limmu</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:8.0em;font-weight:normal;background:#cc9;"><a href="/wiki/Regnal_year" title="Regnal year">Era names</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Chinese_era_name" title="Chinese era name">Chinese</a></li> <li><a href="/wiki/Japanese_era_name" title="Japanese era name">Japanese</a></li> <li><a href="/wiki/Korean_era_name" title="Korean era name">Korean</a></li> <li><a href="/wiki/Vietnamese_era_name" title="Vietnamese era name">Vietnamese</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;line-height:1.2em;background:#cc9;"><a href="/wiki/Calendar" title="Calendar">Calendars</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:8.0em;font-weight:normal;background:#cc9;">Pre-Julian / Julian</th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Roman_calendar" title="Roman calendar">Pre-Julian Roman</a></li> <li><a href="/wiki/Julian_calendar" title="Julian calendar">Original Julian</a></li> <li><a href="/wiki/Proleptic_Julian_calendar" title="Proleptic Julian calendar">Proleptic Julian</a></li> <li><a href="/wiki/Revised_Julian_calendar" title="Revised Julian calendar">Revised Julian</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:8.0em;font-weight:normal;background:#cc9;">Gregorian</th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Gregorian_calendar" title="Gregorian calendar">Gregorian</a></li> <li><a href="/wiki/Proleptic_Gregorian_calendar" title="Proleptic Gregorian calendar">Proleptic Gregorian</a></li> <li><a href="/wiki/Old_Style_and_New_Style_dates" title="Old Style and New Style dates">Old Style and New Style dates</a></li> <li><a href="/wiki/Adoption_of_the_Gregorian_calendar" title="Adoption of the Gregorian calendar">Adoption of the Gregorian calendar</a></li> <li><a href="/wiki/Dual_dating" title="Dual dating">Dual dating</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:8.0em;font-weight:normal;background:#cc9;">Astronomical</th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Lunisolar_calendar" title="Lunisolar calendar">Lunisolar</a> (<a href="/wiki/Hebrew_calendar" title="Hebrew calendar">Hebrew</a>, <a href="/wiki/Hindu_calendar" title="Hindu calendar">Hindu</a>)</li> <li><a href="/wiki/Solar_calendar" title="Solar calendar">Solar</a></li> <li><a href="/wiki/Lunar_calendar" title="Lunar calendar">Lunar</a> (<a href="/wiki/Islamic_calendar" title="Islamic calendar">Islamic</a>)</li> <li><a class="mw-selflink selflink">Astronomical year numbering</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:8.0em;font-weight:normal;background:#cc9;">Others</th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Sexagenary_cycle" title="Sexagenary cycle">Chinese sexagenary cycle</a></li> <li><a href="/wiki/Geologic_Calendar" title="Geologic Calendar">Geologic Calendar</a></li> <li><a href="/wiki/Iranian_calendars" title="Iranian calendars">Iranian</a></li> <li><a href="/wiki/ISO_week_date" title="ISO week date">ISO week date</a></li> <li><a href="/wiki/Mesoamerican_calendars" title="Mesoamerican calendars">Mesoamerican</a> <ul><li><a href="/wiki/Maya_calendar" title="Maya calendar">Maya</a></li> <li><a href="/wiki/Aztec_calendar" title="Aztec calendar">Aztec</a></li></ul></li> <li><a href="/wiki/Winter_count" title="Winter count">Winter count</a></li> <li><a href="/wiki/New_Earth_Time" title="New Earth Time">New Earth Time</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;line-height:1.2em;background:#cc9;"><a href="/wiki/Astronomical_chronology" title="Astronomical chronology">Astronomic time</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0;background:#fff;"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Cosmic_Calendar" title="Cosmic Calendar">Cosmic Calendar</a></li> <li><a href="/wiki/Ephemeris" title="Ephemeris">Ephemeris</a></li> <li><a href="/wiki/Galactic_year" title="Galactic year">Galactic year</a></li> <li><a href="/wiki/Metonic_cycle" title="Metonic cycle">Metonic cycle</a></li> <li><a href="/wiki/Milankovitch_cycles" title="Milankovitch cycles">Milankovitch cycles</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;line-height:1.2em;background:#cc9;"><a href="/wiki/Geologic_time_scale" title="Geologic time scale">Geologic time</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:8.0em;font-weight:normal;background:#cc9;">Concepts</th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Deep_time" title="Deep time">Deep time</a></li> <li><a href="/wiki/Geological_history_of_Earth" title="Geological history of Earth">Geological history of Earth</a></li> <li><a href="/wiki/Geologic_time_scale#Terminology" title="Geologic time scale">Geological time units</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:8.0em;font-weight:normal;background:#cc9;">Standards</th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Global_Standard_Stratigraphic_Age" title="Global Standard Stratigraphic Age">Global Standard Stratigraphic Age (GSSA)</a></li> <li><a href="/wiki/Global_Boundary_Stratotype_Section_and_Point" title="Global Boundary Stratotype Section and Point">Global Boundary Stratotype Section and Point (GSSP)</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:8.0em;font-weight:normal;background:#cc9;">Methods</th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Chronostratigraphy" title="Chronostratigraphy">Chronostratigraphy</a></li> <li><a href="/wiki/Geochronology" title="Geochronology">Geochronology</a></li> <li><a href="/wiki/Isotope_geochemistry" title="Isotope geochemistry">Isotope geochemistry</a></li> <li><a href="/wiki/Law_of_superposition" title="Law of superposition">Law of superposition</a></li> <li><a href="/wiki/Luminescence_dating" title="Luminescence dating">Luminescence dating</a></li> <li><a href="/wiki/Samarium%E2%80%93neodymium_dating" title="Samarium–neodymium dating">Samarium–neodymium dating</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;line-height:1.2em;background:#cc9;"><a href="/wiki/Chronological_dating" title="Chronological dating">Chronological<br />dating</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:8.0em;font-weight:normal;background:#cc9;"><a href="/wiki/Absolute_dating" title="Absolute dating">Absolute dating</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Amino_acid_dating" title="Amino acid dating">Amino acid racemisation</a></li> <li><a href="/wiki/Archaeomagnetic_dating" title="Archaeomagnetic dating">Archaeomagnetic dating</a></li> <li><a href="/wiki/Dendrochronology" title="Dendrochronology">Dendrochronology</a></li> <li><a href="/wiki/Ice_core" title="Ice core">Ice core</a></li> <li><a href="/wiki/Incremental_dating" title="Incremental dating">Incremental dating</a></li> <li><a href="/wiki/Lichenometry" title="Lichenometry">Lichenometry</a></li> <li><a href="/wiki/Paleomagnetism" title="Paleomagnetism">Paleomagnetism</a></li> <li><a href="/wiki/Radiometric_dating" title="Radiometric dating">Radiometric dating</a> <ul><li><a href="/wiki/Lead%E2%80%93lead_dating" title="Lead–lead dating">Lead–lead</a></li> <li><a href="/wiki/K%E2%80%93Ar_dating" title="K–Ar dating">Potassium–argon</a></li> <li><a href="/wiki/Radiocarbon_dating" title="Radiocarbon dating">Radiocarbon</a></li> <li><a href="/wiki/Uranium%E2%80%93lead_dating" title="Uranium–lead dating">Uranium–lead</a></li></ul></li> <li><a href="/wiki/Tephrochronology" title="Tephrochronology">Tephrochronology</a></li> <li><a href="/wiki/Luminescence_dating" title="Luminescence dating">Luminescence dating</a></li> <li><a href="/wiki/Thermoluminescence_dating" title="Thermoluminescence dating">Thermoluminescence dating</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:8.0em;font-weight:normal;background:#cc9;"><a href="/wiki/Relative_dating" title="Relative dating">Relative dating</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Fluorine_absorption_dating" title="Fluorine absorption dating">Fluorine absorption</a></li> <li><a href="/wiki/Nitrogen_dating" title="Nitrogen dating">Nitrogen dating</a></li> <li><a href="/wiki/Obsidian_hydration_dating" title="Obsidian hydration dating">Obsidian hydration</a></li> <li><a href="/wiki/Seriation_(archaeology)" title="Seriation (archaeology)">Seriation</a></li> <li><a href="/wiki/Stratigraphy_(archaeology)" title="Stratigraphy (archaeology)">Stratigraphy</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;line-height:1.2em;background:#cc9;">Genetic methods</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Molecular_clock" title="Molecular clock">Molecular clock</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;line-height:1.2em;background:#cc9;">Linguistic methods</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Glottochronology" title="Glottochronology">Glottochronology</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;line-height:1.2em;background:#cc9;">Related topics</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Chronicle" title="Chronicle">Chronicle</a></li> <li><a href="/wiki/New_Chronology_(Fomenko)" class="mw-redirect" title="New Chronology (Fomenko)">New Chronology</a></li> <li><a href="/wiki/Synchronoptic_view" title="Synchronoptic view">Synchronoptic view</a></li> <li><a href="/wiki/Timeline" title="Timeline">Timeline</a></li> <li><a href="/wiki/Year_zero" title="Year zero">Year zero</a></li> <li><a href="/wiki/Floruit" title="Floruit">Floruit</a></li> <li><a href="/wiki/Terminus_post_quem" title="Terminus post quem">Terminus post quem</a></li> <li><a href="/wiki/ASPRO_chronology" title="ASPRO chronology">ASPRO chronology</a></li></ul> </div></td></tr></tbody></table></div> <div class="navbox-styles"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236075235"></div><div role="navigation" class="navbox" aria-labelledby="Time_measurement_and_standards" style="padding:3px"><table class="nowraplinks hlist mw-collapsible autocollapse navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="3"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239400231"><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Time_measurement_and_standards" title="Template:Time measurement and standards"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Time_measurement_and_standards" title="Template talk:Time measurement and standards"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Time_measurement_and_standards" title="Special:EditPage/Template:Time measurement and standards"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Time_measurement_and_standards" style="font-size:114%;margin:0 4em"><a href="/wiki/Time" title="Time">Time measurement</a> and <a href="/wiki/Time_standard" title="Time standard">standards</a></div></th></tr><tr><td class="navbox-abovebelow" colspan="3"><div> <ul><li><a href="/wiki/Chronometry" title="Chronometry">Chronometry</a></li> <li><a href="/wiki/Orders_of_magnitude_(time)" title="Orders of magnitude (time)">Orders of magnitude</a></li> <li><a href="/wiki/Time_metrology" class="mw-redirect" title="Time metrology">Metrology</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">International standards</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Coordinated_Universal_Time" title="Coordinated Universal Time">Coordinated Universal Time</a> <ul><li><a href="/wiki/UTC_offset" title="UTC offset">offset</a></li></ul></li> <li><a href="/wiki/Universal_Time" title="Universal Time">UT</a></li> <li><a href="/wiki/%CE%94T_(timekeeping)" title="ΔT (timekeeping)">ΔT</a></li> <li><a href="/wiki/DUT1" title="DUT1">DUT1</a></li> <li><a href="/wiki/International_Earth_Rotation_and_Reference_Systems_Service" title="International Earth Rotation and Reference Systems Service">International Earth Rotation and Reference Systems Service</a></li> <li><a href="/wiki/ISO_31-1" title="ISO 31-1">ISO 31-1</a></li> <li><a href="/wiki/ISO_8601" title="ISO 8601">ISO 8601</a></li> <li><a href="/wiki/International_Atomic_Time" title="International Atomic Time">International Atomic Time</a></li> <li><a href="/wiki/12-hour_clock" title="12-hour clock">12-hour clock</a></li> <li><a href="/wiki/24-hour_clock" title="24-hour clock">24-hour clock</a></li> <li><a href="/wiki/Barycentric_Coordinate_Time" title="Barycentric Coordinate Time">Barycentric Coordinate Time</a></li> <li><a href="/wiki/Barycentric_Dynamical_Time" title="Barycentric Dynamical Time">Barycentric Dynamical Time</a></li> <li><a href="/wiki/Civil_time" title="Civil time">Civil time</a></li> <li><a href="/wiki/Daylight_saving_time" title="Daylight saving time">Daylight saving time</a></li> <li><a href="/wiki/Geocentric_Coordinate_Time" title="Geocentric Coordinate Time">Geocentric Coordinate Time</a></li> <li><a href="/wiki/International_Date_Line" title="International Date Line">International Date Line</a></li> <li><a href="/wiki/IERS_Reference_Meridian" title="IERS Reference Meridian">IERS Reference Meridian</a></li> <li><a href="/wiki/Leap_second" title="Leap second">Leap second</a></li> <li><a href="/wiki/Solar_time" title="Solar time">Solar time</a></li> <li><a href="/wiki/Terrestrial_Time" title="Terrestrial Time">Terrestrial Time</a></li> <li><a href="/wiki/Time_zone" title="Time zone">Time zone</a></li> <li><a href="/wiki/180th_meridian" title="180th meridian">180th meridian</a></li></ul> </div></td><td class="noviewer navbox-image" rowspan="9" style="width:1px;padding:0 0 0 2px"><div><span typeof="mw:File"><a href="/wiki/Hourglass" title="Hourglass"><img alt="template illustration" src="//upload.wikimedia.org/wikipedia/commons/thumb/7/70/Marine_sandglass_MMM.jpg/75px-Marine_sandglass_MMM.jpg" decoding="async" width="75" height="175" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/7/70/Marine_sandglass_MMM.jpg/113px-Marine_sandglass_MMM.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/7/70/Marine_sandglass_MMM.jpg/150px-Marine_sandglass_MMM.jpg 2x" data-file-width="1637" data-file-height="3819" /></a></span><br /><span typeof="mw:File"><a href="/wiki/Time_zone" title="Time zone"><img alt="template illustration" src="//upload.wikimedia.org/wikipedia/commons/thumb/6/63/Aleutian_Islands_with_180th_meridian_and_International_Date_Line_%28cropped%29.png/75px-Aleutian_Islands_with_180th_meridian_and_International_Date_Line_%28cropped%29.png" decoding="async" width="75" height="152" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/6/63/Aleutian_Islands_with_180th_meridian_and_International_Date_Line_%28cropped%29.png/113px-Aleutian_Islands_with_180th_meridian_and_International_Date_Line_%28cropped%29.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/6/63/Aleutian_Islands_with_180th_meridian_and_International_Date_Line_%28cropped%29.png/150px-Aleutian_Islands_with_180th_meridian_and_International_Date_Line_%28cropped%29.png 2x" data-file-width="496" data-file-height="1007" /></a></span></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Obsolete standards</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Ephemeris_time" title="Ephemeris time">Ephemeris time</a></li> <li><a href="/wiki/Greenwich_Mean_Time" title="Greenwich Mean Time">Greenwich Mean Time</a></li> <li><a href="/wiki/Prime_meridian" title="Prime meridian">Prime meridian</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Time_in_physics" title="Time in physics">Time in physics</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Absolute_space_and_time" title="Absolute space and time">Absolute space and time</a></li> <li><a href="/wiki/Spacetime" title="Spacetime">Spacetime</a></li> <li><a href="/wiki/Chronon" title="Chronon">Chronon</a></li> <li><a href="/wiki/Continuous_signal" class="mw-redirect" title="Continuous signal">Continuous signal</a></li> <li><a href="/wiki/Coordinate_time" title="Coordinate time">Coordinate time</a></li> <li><a href="/wiki/Cosmological_decade" title="Cosmological decade">Cosmological decade</a></li> <li><a href="/wiki/Discrete_time_and_continuous_time" title="Discrete time and continuous time">Discrete time and continuous time</a></li> <li><a href="/wiki/Proper_time" title="Proper time">Proper time</a></li> <li><a href="/wiki/Theory_of_relativity" title="Theory of relativity">Theory of relativity</a></li> <li><a href="/wiki/Time_dilation" title="Time dilation">Time dilation</a></li> <li><a href="/wiki/Gravitational_time_dilation" title="Gravitational time dilation">Gravitational time dilation</a></li> <li><a href="/wiki/Time_domain" title="Time domain">Time domain</a></li> <li><a href="/wiki/Time-translation_symmetry" title="Time-translation symmetry">Time-translation symmetry</a></li> <li><a href="/wiki/T-symmetry" title="T-symmetry">T-symmetry</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Horology" class="mw-redirect" title="Horology">Horology</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Clock" title="Clock">Clock</a></li> <li><a href="/wiki/Astrarium" title="Astrarium">Astrarium</a></li> <li><a href="/wiki/Atomic_clock" title="Atomic clock">Atomic clock</a></li> <li><a href="/wiki/Complication_(horology)" title="Complication (horology)">Complication</a></li> <li><a href="/wiki/History_of_timekeeping_devices" title="History of timekeeping devices">History of timekeeping devices</a></li> <li><a href="/wiki/Hourglass" title="Hourglass">Hourglass</a></li> <li><a href="/wiki/Marine_chronometer" title="Marine chronometer">Marine chronometer</a></li> <li><a href="/wiki/Marine_sandglass" title="Marine sandglass">Marine sandglass</a></li> <li><a href="/wiki/Radio_clock" title="Radio clock">Radio clock</a></li> <li><a href="/wiki/Watch" title="Watch">Watch</a> <ul><li><a href="/wiki/Stopwatch" title="Stopwatch">stopwatch</a></li></ul></li> <li><a href="/wiki/Water_clock" title="Water clock">Water clock</a></li> <li><a href="/wiki/Sundial" title="Sundial">Sundial</a></li> <li><a href="/wiki/Dialing_scales" title="Dialing scales">Dialing scales</a></li> <li><a href="/wiki/Equation_of_time" title="Equation of time">Equation of time</a></li> <li><a href="/wiki/History_of_sundials" title="History of sundials">History of sundials</a></li> <li><a href="/wiki/Schema_for_horizontal_dials" title="Schema for horizontal dials">Sundial markup schema</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Calendar" title="Calendar">Calendar</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Gregorian_calendar" title="Gregorian calendar">Gregorian</a></li> <li><a href="/wiki/Hebrew_calendar" title="Hebrew calendar">Hebrew</a></li> <li><a href="/wiki/Hindu_calendar" title="Hindu calendar">Hindu</a></li> <li><a href="/wiki/Holocene_calendar" title="Holocene calendar">Holocene</a></li> <li><a href="/wiki/Islamic_calendar" title="Islamic calendar">Islamic</a> (lunar Hijri)</li> <li><a href="/wiki/Julian_calendar" title="Julian calendar">Julian</a></li> <li><a href="/wiki/Solar_Hijri_calendar" title="Solar Hijri calendar">Solar Hijri</a></li> <li><a class="mw-selflink selflink">Astronomical</a></li> <li><a href="/wiki/Dominical_letter" title="Dominical letter">Dominical letter</a></li> <li><a href="/wiki/Epact" title="Epact">Epact</a></li> <li><a href="/wiki/Equinox" title="Equinox">Equinox</a></li> <li><a href="/wiki/Intercalation_(timekeeping)" title="Intercalation (timekeeping)">Intercalation</a></li> <li><a href="/wiki/Julian_day" title="Julian day">Julian day</a></li> <li><a href="/wiki/Leap_year" title="Leap year">Leap year</a></li> <li><a href="/wiki/Lunar_calendar" title="Lunar calendar">Lunar</a></li> <li><a href="/wiki/Lunisolar_calendar" title="Lunisolar calendar">Lunisolar</a></li> <li><a href="/wiki/Solar_calendar" title="Solar calendar">Solar</a></li> <li><a href="/wiki/Solstice" title="Solstice">Solstice</a></li> <li><a href="/wiki/Tropical_year" title="Tropical year">Tropical year</a></li> <li><a href="/wiki/Determination_of_the_day_of_the_week" title="Determination of the day of the week">Weekday determination</a></li> <li><a href="/wiki/Names_of_the_days_of_the_week" title="Names of the days of the week">Weekday names</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Archaeology and geology</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Chronological_dating" title="Chronological dating">Chronological dating</a></li> <li><a href="/wiki/Geologic_time_scale" title="Geologic time scale">Geologic time scale</a></li> <li><a href="/wiki/International_Commission_on_Stratigraphy" title="International Commission on Stratigraphy">International Commission on Stratigraphy</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Astronomical_chronology" title="Astronomical chronology">Astronomical chronology</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Galactic_year" title="Galactic year">Galactic year</a></li> <li><a href="/wiki/Nuclear_timescale" title="Nuclear timescale">Nuclear timescale</a></li> <li><a href="/wiki/Precession" title="Precession">Precession</a></li> <li><a href="/wiki/Sidereal_time" title="Sidereal time">Sidereal time</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Other <a href="/wiki/Unit_of_time" title="Unit of time">units of time</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Instant" title="Instant">Instant</a></li> <li><a href="/wiki/Flick_(time)" title="Flick (time)">Flick</a></li> <li><a href="/wiki/Shake_(unit)" title="Shake (unit)">Shake</a></li> <li><a href="/wiki/Jiffy_(time)" title="Jiffy (time)">Jiffy</a></li> <li><a href="/wiki/Second" title="Second">Second</a></li> <li><a href="/wiki/Minute" title="Minute">Minute</a></li> <li><a href="/wiki/Moment_(unit)" title="Moment (unit)">Moment</a></li> <li><a href="/wiki/Hour" title="Hour">Hour</a></li> <li><a href="/wiki/Day" title="Day">Day</a></li> <li><a href="/wiki/Week" title="Week">Week</a></li> <li><a href="/wiki/Fortnight" title="Fortnight">Fortnight</a></li> <li><a href="/wiki/Month" title="Month">Month</a></li> <li><a href="/wiki/Year" title="Year">Year</a></li> <li><a href="/wiki/Olympiad" title="Olympiad">Olympiad</a></li> <li><a href="/wiki/Lustrum" title="Lustrum">Lustrum</a></li> <li><a href="/wiki/Decade" title="Decade">Decade</a></li> <li><a href="/wiki/Century" title="Century">Century</a></li> <li><a href="/wiki/Saeculum" title="Saeculum">Saeculum</a></li> <li><a href="/wiki/Millennium" title="Millennium">Millennium</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Related topics</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Chronology" title="Chronology">Chronology</a></li> <li><a href="/wiki/Duration_(philosophy)" title="Duration (philosophy)">Duration</a> <ul><li><a href="/wiki/Duration_(music)" title="Duration (music)">music</a></li></ul></li> <li><a href="/wiki/Mental_chronometry" title="Mental chronometry">Mental chronometry</a></li> <li><a href="/wiki/Decimal_time" title="Decimal time">Decimal time</a></li> <li><a href="/wiki/Metric_time" title="Metric time">Metric time</a></li> <li><a href="/wiki/System_time" title="System time">System time</a></li> <li><a href="/wiki/Time_metrology" class="mw-redirect" title="Time metrology">Time metrology</a></li> <li><a href="/wiki/Time_value_of_money" title="Time value of money">Time value of money</a></li> <li><a href="/wiki/Timekeeper" title="Timekeeper">Timekeeper</a></li></ul> </div></td></tr></tbody></table></div>    </div><noscript><img src="https://login.wikimedia.org/wiki/Special:CentralAutoLogin/start?type=1x1" alt="" width="1" height="1" style="border: none; position: absolute;"></noscript> <div class="printfooter" data-nosnippet="">Retrieved from "<a dir="ltr" href="https://en.wikipedia.org/w/index.php?title=Astronomical_year_numbering&oldid=1251825396">https://en.wikipedia.org/w/index.php?title=Astronomical_year_numbering&oldid=1251825396</a>"</div></div> <div id="catlinks" class="catlinks" data-mw="interface"><div id="mw-normal-catlinks" class="mw-normal-catlinks"><a href="/wiki/Help:Category" title="Help:Category">Categories</a>: <ul><li><a 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