Islamic calendar | converting hijri to gregorian date or vice versa

Converting Hijri to Gregorian date or vice versa

Civil and Hijri establishment dates of a library in Old City, Jerusalem

Conversions may be made by using the Tabular Islamic calendar, or, for greatest accuracy (one day in 15,186 years), via the Jewish calendar. Theoretically, the days of the months correspond in both calendars if the displacements which are a feature of the Jewish system are ignored. The table below gives, for nineteen years, the Muslim month which corresponds to the first Jewish month.

Year AD Year AH Muslim
2011 1432 5
2012 1433 5
2013 1434 5
2014 1435 6
2015 1436 6
2016 1437 7
2017 1438 7
2018 1439 7
2019 1440 8
2020 1441 8
Year AD Year AH Muslim
2021 1442 8
2022 1443 9
2023 1444 9
2024 1445 10
2025 1446 10
2026 1447 10
2027 1448 11
2028 1449 11
2029 1450 11

This table may be extended since every nineteen years the Muslim month number increases by seven. When it goes above twelve, subtract twelve and add one to the year AH. From AD412 to AD632 inclusive the month number is 1 and the calculation gives the month correct to a month or so. AD622 corresponds to BH1 and AH1. For earlier years, year BH = (623 or 622) – year AD).

An example calculation: What is the civil date and year AH of the first day of the first month in the year AD 20875?

We first find the Muslim month number corresponding to the first month of the Jewish year which begins in AD20874. Dividing 20874 by 19 gives quotient 1098 and remainder 12. Dividing 2026 by 19 gives quotient 106 and remainder 12. 2026 is chosen because it gives the same remainder on division by 19 as 20874. The two years are therefore (1098–106)=992×19 years apart. The Muslim month number corresponding to the first Jewish month is therefore 992×7=6944 higher than in 2026. To convert into years and months divide by twelve – 6944/12=578 years and 8 months. Adding, we get 1447y 10m + 20874y – 2026y + 578y 8m = 20874y 6m. Therefore, the first month of the Jewish year beginning in AD20874 corresponds to the sixth month of the Muslim year AH20874. The worked example in Conversion between Jewish and civil dates, shows that the civil date of the first day of this month (ignoring the displacements) is Friday, 14 June. The year AH20875 will therefore begin seven months later, on the first day of the eighth Jewish month, which the worked example shows to be 7 January, AD20875 (again ignoring the displacements). The date given by this method, being calculated, may differ by a day from the actual date, which is determined by observation.

A reading of the section which follows will show that the year AH20875 is wholly contained within the year AD20875, also that in the Gregorian calendar this correspondence will occur one year earlier. The reason for the discrepancy is that the Gregorian year (like the Julian) is slightly too long, so the Gregorian date for a given AH date will be earlier and the Muslim calendar catches up sooner.

Current correlations

An Islamic year will be entirely within a Gregorian year of the same number in the year 20874, after which year the number of the Islamic year will always be greater than the number of the concurrent civil year. The Islamic calendar year of 1429 occurred entirely within the civil calendar year of 2008. Such years occur once every 33 or 34 Islamic years (32 or 33 civil years). More are listed here:

 Islamic year within civil year 
Islamic Civil Difference
1060 1650 590
1093 1682 589
1127 1715 588
1161 1748 587
1194 1780 586
1228 1813 585
1261 1845 584
1295 1878 583
1329 1911 582
1362 1943 581
1396 1976 580
1429 2008 579
1463 2041 578
1496 2073 577
1530 2106 576
1564 2139 575

Because a Hijri or Islamic lunar year is between 10 and 12 days shorter than a civil year, it begins 10–12 days earlier in the civil year following the civil year in which the previous Hijri year began. Once every 33 or 34 Hijri years, or once every 32 or 33 civil years, the beginning of a Hijri year (1 Muharram) coincides with one of the first ten days of January. Subsequent Hijri New Years move backward through the civil year back to the beginning of January again, passing through each civil month from December to January.

Other Languages
العربية: تقويم هجري
azərbaycanca: Hicri təqvim
Bân-lâm-gú: Islam Le̍k-hoat
беларуская (тарашкевіца)‎: Мусульманскі каляндар
Esperanto: Islama kalendaro
한국어: 이슬람력
हिन्दी: हिजरी
Bahasa Indonesia: Kalender Hijriyah
interlingua: Calendario islamic
कॉशुर / کٲشُر: اِسلامی تَقويٖم
македонски: Исламски календар
Bahasa Melayu: Takwim Hijrah
日本語: ヒジュラ暦
norsk nynorsk: Muslimsk tidsrekning
oʻzbekcha/ўзбекча: Islomiy taqvim
Simple English: Islamic calendar
slovenčina: Islamský kalendár
slovenščina: Islamski koledar
српски / srpski: Исламски календар
srpskohrvatski / српскохрватски: Islamski kalendar
Basa Sunda: Kalénder Islam
татарча/tatarça: Һиҗри тәкъвим
Türkçe: Hicrî takvim
ئۇيغۇرچە / Uyghurche: ھىجرىيە تەقۋىمى
Tiếng Việt: Lịch Hồi giáo
吴语: 伊斯兰历
粵語: 回曆
中文: 伊斯兰历