Editing Islamic calendar (section)

==History==
{{For|a list of Islamic centuries and the corresponding Gregorian years|Timeline of Islamic history}}

===Pre-Islamic calendar===
{{Main|Pre-Islamic calendar}}
For central Arabia, especially [[Mecca]], there is a lack of epigraphical evidence but details are found in the writings of Muslim authors of the [[Abbasid]] era. Inscriptions of the ancient [[South Arabia]]n calendars reveal the use of a number of local calendars. At least some of these South Arabian calendars followed the [[lunisolar calendar|lunisolar system]]. Both [[al-Biruni]] and [[al-Mas'udi]] suggest that the ancient Arabs used the same month names as the Muslims, though they also record other month names used by the pre-Islamic Arabs.<ref name="EI2-Tarikh"/>{{which|date=March 2021}}

The Islamic tradition is unanimous in stating that Arabs of [[Tihamah]], [[Hejaz]], and [[Najd]] distinguished between two types of months, permitted (''ḥalāl'') and forbidden (''ḥarām'') months.<ref name="EI2-Tarikh"/> The forbidden months were four months during which fighting is forbidden, listed as Rajab and the three months around the [[hajj|pilgrimage]] season, Dhu al-Qa‘dah, Dhu al-Hijjah, and Muharram.<ref name="EI2-Tarikh"/> A similar if not identical concept to the forbidden months is also attested by [[Procopius]], where he describes an armistice that the Eastern Arabs of the Lakhmid al-Mundhir respected for two months in the [[summer solstice]] of 541 CE.<ref name="EI2-Tarikh"/> However, Muslim historians do not link these months to a particular season. The [[Qur'an]] links the four forbidden months with ''Nasī{{'}}'', a word that literally means "postponement".<ref name="EI2-Tarikh"/> According to Muslim tradition, the decision of postponement was administered by the tribe of [[Kinanah]],<ref name=Moberg2/> by a man known as the ''al-Qalammas'' of Kinanah and his descendants (pl. ''qalāmisa'').<ref name=Kitab/>

Different interpretations of the concept of ''Nasī{{'}}'' have been proposed.<ref>For an overview of the various theories and a discussion of the problem of "hindsight chronology" in early and pre-Islamic sources, see [http://etheses.dur.ac.uk/978/1/978.pdf?EThOS%20(BL) Maurice A. McPartlan, ''The Contribution of Qu'rān and Hadīt to Early Islamic Chronology'' (Durham, 1997)] {{Webarchive|url=https://web.archive.org/web/20131105220706/http://etheses.dur.ac.uk/978/1/978.pdf?EThOS%20(BL) |date=5 November 2013 }}.</ref> Some scholars, both Muslim<ref>Mahmud Effendi (1858), as discussed in Sherrard Beaumont Burnaby, ''[https://archive.org/details/elementsofjewish00burnuoft Elements of the Jewish and Muhammadan calendars]'' (London: 1901), pp. 460–470.</ref><ref>According to "Tradition", repeatedly cited by F.C. De Blois.</ref> and Western,<ref name="EI2-Tarikh">F.C. De Blois, "TA’RĪKH": I.1.iv.  "Pre-Islamic and agricultural calendars of the Arabian peninsula", ''The Encyclopaedia of Islam'', 2nd edition, '''X''':260.</ref><ref name=Moberg2>A. Moberg, "NASI'", ''The Encyclopaedia of Islam'', 2nd, VII: 977.</ref> maintain that the [[Pre-Islamic Arabia|pre-Islamic]] calendar used in central Arabia was a purely lunar calendar similar to the modern Islamic calendar. According to this view, ''Nasī{{'}}'' is related to the pre-Islamic practices of the Meccan Arabs, where they would alter the distribution of the forbidden months within a given year without implying a calendar manipulation. This interpretation is supported by Arab historians and lexicographers, like [[Ibn Hisham]], [[Ibn Manzur]], and the corpus of [[tafsir|Qur'anic exegesis]].<ref>{{Cite book|edition=4th|publisher=Al-maktaba al-tijāriyya|last=Muḥammad al-Khuḍarī Bayk|title=Muḥāḍarāt tārīkh al-Umam al-Islāmiyya|year=1935|pages=59–60|volume=2}}</ref>

This is corroborated by an early [[Sabaic]] inscription, where a religious ritual was "postponed" (''ns'w'') due to war. According to the context of this inscription, the verb ''ns'’'' has nothing to do with intercalation, but only with moving religious events within the calendar itself. The similarity between the religious concept of this ancient inscription and the Qur'an suggests that non-calendaring postponement is also the Qur'anic meaning of ''Nasī{{'}}''.<ref name="EI2-Tarikh"/> The ''[[Encyclopaedia of Islam]]'' concludes "The Arabic system of [Nasī'] can only have been intended to move the Hajj and the fairs associated with it in the vicinity of Mecca to a suitable season of the year. It was not intended to establish a fixed calendar to be generally observed."<ref>The Encyclopedia of Islam, 2nd edition, Index, p. 441.</ref> The term "fixed calendar" is generally understood to refer to the non-intercalated calendar.

Others concur that it was originally a lunar calendar, but suggest that about 200 years before the [[Hijra (Islam)|Hijra]] it was transformed into a [[lunisolar calendar]] containing an [[Intercalation (timekeeping)|intercalary month]] added from time to time to keep the pilgrimage within the season of the year when merchandise was most abundant. This interpretation was first proposed by the medieval Muslim astrologer and astronomer [[Abu Ma'shar al-Balkhi]], and later by [[al-Biruni]],<ref name=Kitab>[[Ja'far ibn Muhammad Abu Ma'shar al-Balkhi|Abu Ma'shar al-Balkhi]] (787–886), ''[http://gallica.bnf.fr/ark:/12148/bpt6k93171b.image.f166.langFR Kitab al-Uluf] {{Webarchive|url=https://web.archive.org/web/20110703090924/http://gallica.bnf.fr/ark:/12148/bpt6k93171b.image.f166.langFR |date=3 July 2011 }}'', ''Journal Asiatique'', series 5, '''xi''' (1858) 168+. {{in lang|fr|ar}}</ref><ref name="Nasi">{{cite book |url=https://archive.org/details/chronologyofanci00biru |last=al-Biruni |first=Abu Rayhan Muhammad ibn Ahmad |author-link= al-Biruni|translator-last= Sachau |translator-first=C. Edward |translator-link=Eduard Sachau|title="Intercalation of the Ancient Arabs", The Chronology of Ancient Nations |year=1879 |location=London |publisher=William H. Allen|pages=[https://archive.org/details/chronologyofanci00biru/page/13 13]–14, 73–74}}</ref> [[al-Mas'udi]], and some western scholars.<ref name=Moberg1>A. Moberg, "[https://books.google.com/books?id=9JQ3AAAAIAAJ NASI']", ''E.J. Brill's first encyclopaedia of Islam''.</ref> This interpretation considers ''Nasī{{'}}'' to be a synonym to the Arabic word for "intercalation" (''kabīsa''). The Arabs, according to one explanation mentioned by Abu Ma'shar, learned of this type of intercalation from the Jews.<ref name=Moberg2/><ref name=Kitab/><ref name="Nasi"/> The Jewish ''Nasi'' was the official who decided when to intercalate the Jewish calendar.<ref>Bab. Talmud, Sanhedrin, p. 11.</ref>{{Full citation needed|date=August 2022}} Some sources say that the Arabs followed the Jewish practice and intercalated seven months over nineteen years, or else that they intercalated nine months over 24 years; there is, however, no consensus among scholars on this issue.<ref>Bonner 2011, page 21.</ref>{{Full citation needed|date=August 2022}}

===Prohibiting Nasī' <span class="anchor" id="Prohibiting Nasi'"></span><span class="anchor" id="Prohibiting Nasi"></span>===
{{further|Nasi'}}
<!----Please see [[Talk:Muhammad/FAQ]] and discuss on the talk page before removing the following image:---->[[File:Maome.jpg|thumb|Illustration of Muhammad prohibiting Nasī'. Found in an illustrated copy of [[Abū Rayḥān al-Bīrūnī|Al-Biruni]]'s ''[[The Remaining Signs of Past Centuries]]'' (17th-century copy of an early 14th-century [[Ilkhanate|Ilkhanid]] manuscript).<ref>From an illustrated manuscript of Al-Biruni's 11th-century ''[[Vestiges of the Past]]'' (Bibliothèque Nationale, Paris, Arabe 1489 fol. 5v. (Bibliothèque Nationale on-line catalog). See also: Robert Hillenbrand, "Images of Muhammad in al-Bīrūnī's Chronology of Ancient Nations", in: R. Hillenbrand (ed.), ''Persian Painting from the Mongols to the Qajars: Studies in Honour of Basil W. Robinson'' (London/New York: I.B. Tauris Publishers, 2000), pp. 129–46.</ref>]]

[[Nasi']] is interpreted to signify either the postponement of the pre-Islamic month of Hajj, or the (also pre-Islamic) practice of [[intercalation (timekeeping)|intercalation]]{{snd}} periodic insertion of an additional month to reset the calendar into accordance with the seasons.

In the tenth year of the Hijra, as documented in the [[Qur'an]] ([[At-Tawba|Surah At-Tawbah (9)]]:36–37), Muslims believe [[God in Islam|God]] revealed the "prohibition of the Nasī{{'"}}.

{{Blockquote|Indeed, the number of months ordained by Allah is twelve—in Allah's Record since the day He created the heavens and the earth—of which four are sacred. That is the Right Way. So do not wrong one another during these months. And together fight the polytheists as they fight against you together. And know that Allah is with those mindful ˹of Him˺.<br>
Reallocating the sanctity of ˹these˺ months is an increase in disbelief, by which the disbelievers are led ˹far˺ astray. They adjust the sanctity one year and uphold it in another, only to maintain the number of months sanctified by Allah, violating the very months Allah has made sacred. Their evil deeds have been made appealing to them. And Allah does not guide the disbelieving people.|{{qref|9|36|c=y}}}}

The prohibition of Nasī' would presumably have been announced when the intercalated month had returned to its position just before the month of Nasi' began. If Nasī' meant intercalation, then the number and the position of the intercalary months between AH 1 and AH 10 are uncertain; western calendar dates commonly cited for key events in early Islam such as the [[Hegira|Hijra]], the [[Battle of Badr]], the [[Battle of Uhud]] and the [[Battle of the Trench]] should be viewed with caution as they might be in error by one, two, three or even four lunar months. This prohibition was mentioned by Muhammad during the [[The Farewell Sermon|farewell sermon]] which was delivered on 9 Dhu al-Hijjah AH 10 (Julian date Friday 6 March 632 CE) on [[Mount Arafat]] during the [[The Farewell Pilgrimage|farewell pilgrimage]] to Mecca.{{citation needed|date=October 2016}}

{{blockquote|Certainly the Nasi' is an impious addition, which has led the infidels into error. One year they authorise the Nasi', another year they forbid it. They observe the divine precept with respect to the number of the sacred months, but in fact they profane that which God has declared to be inviolable, and sanctify that which God has declared to be profane. Assuredly time, in its revolution, has returned to such as it was at the creation of the heavens and the earth. In the eyes of God the number of the months is twelve. Among these twelve months four are sacred, namely, Rajab, which stands alone, and three others which are consecutive.|Translated by Sherrard Beaumont Burnaby<ref>Sherrard Beaumont Burnaby, ''[https://archive.org/details/elementsofjewish00burnuoft Elements of the Jewish and Muhammadan calendars]'' (London: 1901) 370.</ref>}}

The three successive sacred (forbidden) months mentioned by Muhammad (months in which battles are forbidden) are [[Dhu al-Qadah|Dhu al-Qa'dah]], [[Dhu al-Hijjah]], and [[Muharram]], months 11, 12, and 1 respectively. The single forbidden month is [[Rajab]], month 7. These months were considered forbidden both within the new Islamic calendar and within the old pagan Meccan calendar.<ref>{{cite news |title=Islamic New Year: To celebrate, or not to celebrate? |url=https://nation.com.pk/05-Oct-2016/islamic-new-year-to-celebrate-or-not-to-celebrate |work=The Nation |date=5 October 2016 |language=en |access-date=20 August 2020 |archive-date=10 August 2021 |archive-url=https://web.archive.org/web/20210810091710/https://nation.com.pk/05-Oct-2016/islamic-new-year-to-celebrate-or-not-to-celebrate |url-status=live }}</ref><ref name="EI2-Tarikh"/><ref>{{cite news |title=The four sacred months |url=https://saudigazette.com.sa/article/152932 |work=Saudigazette |date=15 April 2016 |language=en |access-date=21 August 2020 |archive-date=10 August 2020 |archive-url=https://web.archive.org/web/20200810220521/https://saudigazette.com.sa/article/152932 |url-status=live }}</ref><ref>{{cite news |title=Muharram 2020: Al Hijri date, significance of the Islamic New Year |url=https://www.hindustantimes.com/more-lifestyle/muharram-2020-al-hijri-date-and-significance-of-the-islamic-new-year/story-XfqdLHudDcI20RVWKQtOzL.html |work=[[Hindustan Times]] |date=20 August 2020 |language=en |access-date=21 August 2020 |archive-date=21 August 2020 |archive-url=https://web.archive.org/web/20200821071634/https://www.hindustantimes.com/more-lifestyle/muharram-2020-al-hijri-date-and-significance-of-the-islamic-new-year/story-XfqdLHudDcI20RVWKQtOzL.html |url-status=live }}</ref><ref>{{cite web |title=The beginning of a new Islamic year |url=https://gulf-times.com/story/671105/The-beginning-of-a-new-Islamic-year |website=Gulf-Times |language=ar |date=20 August 2020 |access-date=21 August 2020 |archive-date=21 August 2020 |archive-url=https://web.archive.org/web/20200821072520/https://gulf-times.com/story/671105/The-beginning-of-a-new-Islamic-year |url-status=live }}</ref>