List of calendars


This is a list of calendars. Included are historical calendars as well as proposed ones. Historical calendars are often grouped into larger categories by cultural sphere or historical period; thus O'Neil distinguishes the groupings Egyptian calendars, Babylonian calendars, Indian calendars, Chinese calendars and Mesoamerican calendars.
These are not specific calendars but series of historical calendars undergoing reforms or regional diversification.
In Classical Antiquity, the Hellenic calendars inspired the Roman calendar, including the solar Julian calendar introduced in 45 BC. Many modern calendar proposals, including the Gregorian calendar itself, are in turn modifications of the Julian calendar.

List of calendars

In the list below, specific calendars are given, listed by calendar type, time of introduction, and the context of use and cultural or historical grouping.
Regional or historical groups: Hijri calendar, Mayan, Aztecan, Egyptian, Mesopotamian, Iranian, Hindu, Buddhist, Pre-Columbian Mesoamerican, Hellenic, Julian or Gregorian-derived.
Calendars fall into four types, lunisolar, solar, lunar, seasonal, besides calendars with "years" of fixed length, with no intercalation. Most pre-modern calendars are lunisolar. The seasonal calendars rely on changes in the environment rather than lunar or solar observations. The Islamic and some Buddhist calendars are lunar, while most modern calendars are solar, based on either the Julian or the Gregorian calendars.
Some "calendars" listed are identical to the Gregorian calendar except for substituting regional month names or using a different calendar era.
For example, the Thai solar calendar is the Gregorian calendar using a different era and different names for the Gregorian months.
Nametypegroupintroductionusagecomments
Vikram samwatLunisolarIndian
Ancient India-
Egyptian calendarfixed EgyptianBronze AgeMiddle KingdomThe year is based on the heliacal rising of Sirius and divided into the three seasons of akhet, peret and shemu. The heliacal rising of Sothis returned to the same point in the calendar every 1,460 years.
Umma calendarlunisolarMesopotamianBronze AgeSumer/MesopotamiaRecorded in Neo-Sumerian records, presumably based on older sources.
Pentecontad calendarsolarMesopotamianBronze AgeAmoritesA Bronze Age calendar in which the year is divided into seven periods of fifty days, with an annual supplement of fifteen or sixteen days for synchronisation with the solar year.
Four Seasons and Eight Nodes solarChineseBronze AgeChinaThe years is divided into four seasons, and each season is divided into a festival and three months. The start and middle of each season is the key node of the year.
Gezer CalendarlunarMesopotamian1000 BCIsrael/CanaanThe years are divided into monthly or bi-monthly periods and attributes to each a duty such as harvest, planting, or tending specific crops.
Roman calendarlunisolarRoman713 BCRoman RepublicBased on the reforms introduced by Numa Pompilius in c. 713 BC.
Six Ancient Calendars lunisolarChineseIron AgeChinaSix classical calendars: Huangdi, Zhuanxu, Xia, Yin, Zhou's calendar and Lu.
Nisg̱a'aseasonal / lunisolarIndigenous North AmericaNisg̱a'aThe Nisga’a calendar revolves around harvesting of foods and goods used. The original year followed the various moons throughout the year.
HaidalunarIndigenous North AmericaHaidaThe Haida calendar is a lunar calendar broken into two seasons of six months each with an occasional thirteenth month between seasons.
InuitseasonalIndigenous North AmericaInuitThe Inuit calendar is based on between six and eight seasons as solar and lunar timekeeping methods do not work in the polar regions.
Haab'fixed Pre-Columbian 1st millennium BCMaya
Tzolk'infixed Pre-Columbian 1st millennium BCMaya
Xiuhpohuallifixed Pre-Columbian Aztecs
Tonalpohuallifixed Pre-Columbian Aztecs
Attic calendarlunisolar Hellenic6th century BCClassical AthensThe year begins with the new moon after the summer solstice. It was introduced by the astronomer Meton in 432 BC. by Academy of Episteme.
Old Persian calendarlunisolarIranian4th century BCPersian EmpireBased on earlier Babylonian/Mesopotamian models
Seleucid calendarlunisolarHellenic/Babylonian4th century BCSeleucid EmpireCombination of the Babylonian calendar, ancient Macedonian month names and the Seleucid era.
Genesis Calendar lunisolarChineseHan dynastyChinaIntroduced the "month without mid-climate is intercalary" rule; based on a solar year of 365 days and a lunar month of 29 days.
Ptolemaic calendarlunisolarEgyptian238 BCPtolemaic EgyptThe Canopic reform of 238 BC introduced the leap year every fourth year later adopted in the Julian calendar. The reform eventually went into effect with the introduction of the "Alexandrian calendar" by Augustus in 26/25 BC, which included a 6th epagomenal day for the first time in 22 BC.
Julian calendarsolarRoman45 BCWestern WorldRevision of the Roman Republican calendar, in use in the Roman Empire and the Christian Middle Ages, and remains in use as liturgical calendar of Eastern Orthodox Churches.
Coptic calendarsolarEgyptian1st centuryCoptic Orthodox ChurchBased on both the Ptolemaic calendar and the Julian calendar
Ethiopian calendarsolarEgyptian1st centuryEthiopia, Ethiopian Christiansthe calendar associated with Ethiopian Church, based on the Coptic calendar
Berber calendarsolarJulianIn Roman timesNorth AfricaJulian calendar used for agricultural work.
Qumran calendrical textsfixed —c. 1st centurySecond Temple JudaismDescription of a division of the year into 364 days, also mentioned in the pseudepigraphical Book of Enoch.
Gaulish calendarlunisolarGauls/Celts Iron AgeGauls/CeltsEarly calendars used by Celtic peoples prior to the introduction of the Julian calendar, reconstruction mostly based on the Coligny calendar, which may be partially influenced by the Julian calendar.
Zoroastrian calendarfixed Iranian3rd centurySassanid PersiaBased on both the Old Persian and Seleucid calendars. Introduced in AD 226, reformed in AD 272, and again several times in the 5th to 7th centuries.
Chinese Calendar, Dàmíng origin lunisolarChinese510ChinaCreated by Zu Chongzhi, most accurate calendar in the world at its invention
Japanese calendarlunisolarChinese-derived6th centuryJapanUmbrella term for calendars historically and currently used in Japan, in the 6th century derived from the Chinese calendar
Chinese Calendar, Wùyín originlunisolarChinese619ChinaFirst Chinese calendar to use the true moon motion
Islamic calendarlunarMuslim632IslamBased on the observational lunisolar calendars used in Pre-Islamic Arabia. Remains in use for religious purposes in the Islamic world.
Pyu calendarlunisolarHindu/Buddhist-derived640mainland Southeast AsiaTraditional calendar of Southeast Asia, in use until the 19th century. Traditionally said to originate in 640 in Sri Ksetra Kingdom, one of the Burmese Pyu city-states.
Nepal SambatlunarBuddhist/ Hindu9th centuryNepalA lunar Buddhist calendar traditional to Nepal, recognition in Nepal in 2008.
Byzantine calendarsolarJulian988Ecumenical Patriarchate of ConstantinopleJulian calendar with Anno Mundi era in use c. 691 to 1728.
Armenian calendarfixed Iranianmedievalmedieval ArmeniaCalendar used in medieval Armenia and as liturgical calendar of the Armenian Apostolic Church. Derived from the Zoroastrian. It uses the era AD 552. In modern Armenian nationalism, an alternative era of 2492 BC is sometimes used.
Bulgar calendarsolarBulgarianBronze AgeVolga BulgariaA reconstruction based on a short 15th-century transcript in Church Slavonic called Nominalia of the Bulgarian Khans, which contains 10 pairs of calendar terms.
Florentine calendarsolarJulianmedievalRepublic of FlorenceVariant of the Julian calendar in use in medieval Florence
Pisan calendarsolarJulianmedievalRepublic of PisaVariant of the Julian calendar in use in medieval Pisa
Tamil calendarsolarHindumedievalTamil NaduThe Hindu calendar used in Tamil Nadu
Nepali calendarsolarHindu/ BuddhistmedievalNepalOne of the Hindu calendars
Bengali calendarlunisolarBengalimedievalBengalRevised in 1987.
Thai lunar calendarlunisolarHindu/BuddhistmedievalThailandA Buddhist calendar
Pawukon calendarfixed HinduBali
Old Icelandic calendarsolar10th centurymedieval Icelandpartly inspired by the Julian calendar and partly by older Germanic calendar traditions. Leap week calendar based on a year of 364 days.
Jalali calendarsolarIranian1079Seljuk SultanateA calendar reform commissioned by Sultan Jalal al-Din Malik Shah I
Hebrew calendarlunisolarBabylonian/Seleucid-derived11th/12th centuryJudaismrecorded by Maimonides in the Mishneh Torah, resulting from various reforms and traditions developing since Late Antiquity. The Anno Mundi era gradually replaced the Seleucid era in Rabbinical literature in the 11th century.
Tibetan calendarlunisolarBuddhist/Chinese-derived13th centuryTibetThe Kalacakra, a Buddhist calendar introduced in 13th-century Tibet
Seasonal Instruction solarChinese1281ChinaBased on a solar year of 365.2425
Runic calendarsolarJulian13th centurySwedenA written representation of the Metonic cycle used in medieval and early modern Sweden, allowing to calculate the dates of the full moons relative to the Julian date. The introduction of the Gregorian calendar in Sweden in 1753 rendered the runic calendars unusable.
Six Imperial Calendars solarChineseMing dynastyChinaIn use 1368-1644
Incan calendarlunisolarPre-Columbian15th centuryInca Empire
Muisca calendarlunisolarPre-Columbian15th centuryMuiscaComplex lunisolar calendar with three different years, composed of months divided into thirty days. After the Spanish conquest of the Muisca Confederation in present-day central Colombia in 1537 first replaced by the European Julian and as of 1582 the Gregorian calendar.
Chula SakaratlunisolarBurmese16th centurySoutheast Asia
Gregorian calendarsolarJulian-derived1582worldwideIntroduced as a reform of the Julian calendar in the Roman Catholic church, since the 20th century in de facto use worldwide.
Javanese calendarlunarIslamic influenced1633JavaBased on the Hindu calendar using the Saka era, but changed to the lunar year following the Islamic calendar.
Seasonal Constitution solarChinese1645ChinaFirst Chinese Calendar to use the true motion of the sun.
Swedish calendarsolarJulian-derived1700SwedenPart of the controversy surrounding the adoption of the Gregorian calendar, in use 1700–1712.
Astronomical year numberingsolarJulian-derived1740astronomyA mixture of Julian and Gregorian calendar, giving dates before 1582 in the Julian calendar, and dates after 1582 in the Gregorian calendar, counting 1 BC as year zero, and negative year numbers for 2 BC and earlier.
French Republican CalendarsolarGregorian1793First French RepublicIn use in revolutionary France 1793 to 1805.
PancronometersolarGregorian1745—Universal Georgian Calendar proposed by Hugh Jones
Rumi calendarsolarJulian1839Ottoman EmpireJulian calendar using the Hijri era introduced in the Ottoman Empire.
Positivist calendarsolarGregorian1849—solar calendar with 13 months of 28 days.
Badí‘ calendarsolarBahá'í1873Bahá'íUses a year of 19 months of 19 days each and a 1844 era. Also known as the "Bahá'í Calendar" or the "Wondrous Calendar".
Thai solar calendarsolarGregorian1888ThailandThe Gregorian calendar but using the Buddhist Era
Invariable CalendarsolarGregorian1900—Gregorian calendar with four 91-day quarters of 13 weeks
International Fixed CalendarsolarGregorian1902—A "perpetual calendar" with a year of 13 months of 28 days each.
Minguo calendarsolarGregorian1912Republic of ChinaMonths and days use the Gregorian calendar, introduced in China in 1912.
Revised Julian calendarsolarJulian-derived1923some Orthodox churchescurrently synchronized with the Gregorian calendar, but different leap rule and cycle, also called Meletian calendar or Milanković calendar, after Serbian scientist Milutin Milanković who developed it.
Solar Hijri calendarsolarIranian/Islamic1925Iran, AfghanistanNew Year is the day of the astronomical vernal equinox. The calendar as introduced in 1925 revived Iranian month names but counted the years of the Hijri era. The era was changed in 1976 to 559 BC, but was reverted to the Hijri era after the Iranian Revolution.
Era FascistasolarGregorian1926ItalyEpoch is 29 October 1922; in use from 1926-1943
Soviet calendarsolarGregorian1929Soviet UnionGregorian calendar with 5- and 6-day weeks, used during 1929 to 1940.
World CalendarsolarGregorian1930—Perpetual calendar with 1–2 off-week days, preferred and almost adopted by the United Nations in 1950s
Pax CalendarsolarGregorian1930—Leap week calendar
Pataphysical calendarsolarGregorian1949—Absurdist variant of the Gregorian calendar by Alfred Jarry.
Indian national calendarsolarGregorian-derived1957Republic of IndiaGregorian calendar with months based in traditional Hindu calendars and numbering years based on the Saka era.
Assyrian calendarlunarBabylonian1950sAssyrianismLunar calendar with an "Assyrian era" of 4750 BC, introduced in Assyrian nationalism in the 1950s
Discordian calendarsolarGregorian1963DiscordianismCalendar invented in the context of the absurdist or parody religion of Discordianism, Gregorian calendar variant with a year consisting of five 73-day seasons.
World Season CalendarsolarGregorian1973—Divides the year into four seasons.
Dreamspelllunar/solar galacticMayan1990esotericism13 months of 28 days each, synchronized with the Maya 260-day Tzolkin, calibrated to the Chilam Balam timing systems
Tranquility CalendarsolarGregorian1989—Modification of the International Fixed Calendar
Holocene calendarsolarGregorian1993—The Gregorian calendar with the era shifted by 10,000 years.
Juche era calendarsolarGregorian1997North KoreaGregorian calendar with the era 1912
Nanakshahi calendarsolarGregorian-derived1998SikhismGregorian calendar with months based in traditional Hindu calendars and numbering years based on the era 1469.
Symmetry454solarGregorian2004—Leap week calendar with 4:5:4 weeks per month
Hanke-Henry Permanent CalendarsolarGregorian2004—Leap week calendar with 30:30:31 days per month, revised in 2011 and 2016
Igbo calendarlunarIndigenous2009Igbo peopleproposal based in Igbo tradition dating back to 13th century, 13 lunar months of 28 days divided into seven 4-day periods, plus leap days.

Variant month names

Regional or historical names for lunations or Julian/Gregorian months
Traditionculturecomments
Germanic calendarGermanicMedieval records of Germanic names of lunar months later equated with the Julian months.
Berber calendarBerberreconstructed medieval Berber-language names of the Julian months used in pre-Islamic North Africa
Lithuanian calendarLithuaniaLithuanian names for the Gregorian months and days of the week, officially recognized in 1918.
Rapa Nui calendarEaster IslandsThirteen names of lunar months recorded in the 19th century.
Xhosa calendarXhosa people
TurkmenTurkmenistanTurkmen names officially adopted in 2002 following Ruhnama by president-for-life Saparmurat Niyazov.
Hellenic calendarsHellenistic GreeceA great variety of regional month names in Ancient Greece, mostly attested in the 2nd century BC.
Slavic calendarSlavicLocal month names in various Slavic countries, based on weather patterns and conditions, and agricultural activities that take place in each respective month.
Romanian calendarRomaniaTraditional names for the twelve months of the Gregorian calendar, which are usually used by the Romanian Orthodox Church.

Non-standard weeks

Traditionweek lengthcomments
Balivarious
Korea5 days
Java5 days
Discordian5 days
Akan6 daysA traditional "six-day week" which combined with the Gregorian seven-day week gave rise to a 42-day cycle.
Ancient Rome8 daysThe Roman nundinal cycle.
Burmese8 days
Celtic8 daysreconstructed.
Baltic9 daysLinguistic reconstruction; the Gediminas Sceptre indicated that a week lasted for nine days during King Gediminas' reign.
Chinese10 days
Egyptian Calendar10 daysThe 10-day period was known as decans or decades
French Republican Calendar10 days
Aztecs13 daysTrecena, division of the Tonalpohualli 260-day period

Calendaring and timekeeping standards