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 (1976) distinguishes the groupings Egyptian calendars (Ancient Egypt), Babylonian calendars (Ancient Mesopotamia), Indian calendars (Hindu and Buddhist traditions of the Indian subcontinent), 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 introduced in 1582 AD, contains modifications from that of the Julian calendar.
In the list below, specific calendars are given, listed by calendar type (solar, lunisolar or lunar), time of introduction (if known), and the context of use and cultural or historical grouping (if applicable). Where appropriate, the regional or historical group (Jewish calendar, Hijri calendar, Sikh, Mayan, Aztecan, Egyptian, Mesopotamian, Iranian, Hindu, Buddhist, Pre-Columbian Mesoamerican, Hellenic, Julian or Gregorian-derived) is noted.
Calendars fall into four types: lunisolar, solar, lunar and seasonal. Most pre-modern calendars are lunisolar. The seasonal calendars rely on changes in the environment (e.g., "wet season", "dry season") 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 epoch. For example, the Thai solar calendar (introduced 1888) is the Gregorian calendar using a different epoch (543 BC) and different names for the Gregorian months (Thai names based on the signs of the zodiac).
| Name | Type | Group | Introduction | Usage | Comments | |
|---|---|---|---|---|---|---|
| lunisolar | Canaan/Mesopotamian | Circa 3761 BC | Western World | It is based on lunar months with the intercalation of an additional month every 2 to 3 years to bring the cycle closer to the solar cycle. It is used to determine the dates for Jewish holidays and the appropriate public reading of Torah portions, yahrzeits (dates that commemorate the death of a relative), daily Psalm readings, and many other holidays, festivals and ceremonial uses. | ||
| fixed (365 days) | Egyptian | Bronze Age | The year is based on the heliacal rising of Sirius (Sothis) and divided into the three seasons of akhet (Inundation), peret (Growth) and shemu (Harvest). The heliacal rising of Sothis returned to the same point in the calendar every 1,460 years (a period called the Sothic cycle).[1] | |||
| lunisolar | Mesopotamian | Sumer/Mesopotamia | Recorded in Neo-Sumerian records (21st century BC), presumably based on older (Ur III) sources. | |||
| solar | Mesopotamian | Bronze Age | A 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 | solar | Bronze Age(?) | China | The 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. | ||
| unknown | Mesopotamian | 1000 BC | Israel/Canaan | The years are divided into monthly or bi-monthly periods and attributes to each a duty such as harvest, planting, or tending specific crops. | ||
| lunisolar | 713 BC | Based on the reforms introduced by Numa Pompilius in . | ||||
| Six Ancient Calendars | lunisolar | China | Six classical (Zhou era) calendars: Huangdi, Zhuanxu, Xia, Yin, Zhou's calendar and Lu. | |||
| seasonal / lunisolar | Indigenous North America | The Nisga’a calendar revolves around harvesting of foods and goods used. The original year followed the various moons throughout the year. | ||||
| lunisolar | Indigenous North America | The Haida calendar is a lunar calendar broken into two seasons (winter and summer) of six months each with an occasional thirteenth month between seasons. | ||||
| seasonal | Indigenous North America | The Inuit calendar is based on between six and eight seasons as solar and lunar timekeeping methods do not work in the polar regions. | ||||
| fixed (365 days) | Pre-Columbian (Maya) | 1st millennium BC | Maya | |||
| fixed (260 days) | Pre-Columbian (Maya) | 1st millennium BC | Maya | |||
| fixed (365 days) | Pre-Columbian (Aztec) | Aztecs | ||||
| fixed (260 days) | Pre-Columbian (Aztec) | Aztecs | ||||
| lunisolar (354/384 days) | 6th century BC | The year begins with the new moon after the summer solstice. It was introduced by the astronomer Meton in 432 BC. Reconstructed by Academy of Episteme. | ||||
| lunisolar(?) | 4th century BC(?) | Based on earlier Babylonian/Mesopotamian models | ||||
| lunisolar | Hellenic/Babylonian | 4th century BC | Combination of the Babylonian calendar, ancient Macedonian (Hellenic) month names and the Seleucid era. | |||
| Genesis Calendar | lunisolar | China | Introduced the "month without mid-climate is intercalary" rule; based on a solar year of 365 days and a lunar month of 29 days (19 years=235 months=6939 days). | |||
| solar | Egyptian | 238 BC | The 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" (or Julian calendar) by Augustus in 26/25 BC, which included a 6th epagomenal day for the first time in 22 BC. | |||
| solar | Roman | 45 BC | Western World | Revision 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. | ||
| solar | Kurdish | is a calendar used in the Kurdistan region of Iraq alongside the Islamic and Gregorian calendar. The First day in this month is called "Newroz" it means "New Day". The start of the calendar is marked by the Battle of Nineveh, a conquest of the Assyrians by the Medes and the Babylonians in 612 BC. | ||||
| solar | Egyptian | 1st century | Based on both the Ptolemaic calendar and the Julian calendar | |||
| solar | Ethiopian | 1st century | Ethiopia, Ethiopian Christians, Eritrea, Eritrean Christians | the calendar associated with Ethiopian and Eritrean Churchs, based on the Coptic calendar | ||
| solar | Julian | In Roman times | North Africa | Julian calendar used for agricultural work. | ||
| fixed (364 days) | — | Description of a division of the year into 364 days, also mentioned in the pseudepigraphical Book of Enoch (the "Enoch calendar"). | ||||
| lunisolar | Gauls/Celts | Iron Age | Early calendar used by Celtic peoples prior to the introduction of the Julian calendar, on a bronze plaque c. AD 200 but likely some centuries older. | |||
| fixed (365 days) | Iranian | 3rd century | Based on both the Old Persian and Seleucid (Hellenic) calendars. Introduced in AD 226, reformed in AD 272, and again several times in the 5th to 7th centuries. | |||
| Chinese Calendar, Dàmíng origin | lunisolar | 510 | China | Created by Zu Chongzhi, most accurate calendar in the world at its invention | ||
| Korean calendar | lunisolar | Chinese-derived | 6th century | Korea | Introduced from China, went through Korea to Japan. | |
| lunisolar | Chinese-derived | 6th century | Japan | Umbrella term for calendars historically and currently used in Japan, in the 6th century derived from the Chinese calendar. | ||
| Chinese Calendar, Wùyín origin | lunisolar | 619 | China | First Chinese calendar to use the true moon motion | ||
| Islamic calendar (Lunar Hijri calendar) | lunar | Muslim | 632 | Islam | Based on the observational lunisolar calendars used in Pre-Islamic Arabia. Remains in use for religious purposes in most of the Islamic world. | |
| lunisolar | Hindu/Buddhist-derived | 640 | Traditional calendar of Southeast Asia, in use until the 19th century. Traditionally said to originate in 640 (the calendar era) in Sri Ksetra Kingdom, one of the Burmese Pyu city-states. | |||
| solar | Julian | 988 | Julian calendar with Anno Mundi era in use c. 691 to 1728. | |||
| fixed (365 days) | Iranian | medieval | Calendar used in medieval Armenia and as liturgical calendar of the Armenian Apostolic Church. Derived from the Zoroastrian (or related medieval Iranian calendars such as the Sogdian/Choresmian ones[2]). It uses the era AD 552. In modern Armenian nationalism, an alternative era of 2492 BC is sometimes used. | |||
| solar | Bulgarian | Bronze Age | A reconstruction based on a short 15th-century transcript in Church Slavonic called Nominalia of the Bulgarian Khans, which contains 10 pairs of calendar terms. | |||
| solar | Julian | Medieval | Republic of Florence | Variant of the Julian calendar in use in medieval Florence | ||
| solar | Julian | Medieval | Republic of Pisa | Variant of the Julian calendar in use in medieval Pisa | ||
| solar | Hindu | Ancient | The Hindu calendar used in Tamil Nadu | |||
| sidereal solar | Hindu | 825 | It is believed that the era was started by the Syrian Christian saints Mar Sabor and Mar Proth who arrived in Kollam in the 9th century CE. This event is recorded in the Kollam Tarisappalli copper plates issued to them.[3] [4] [5] The news of the physical disappearance of Sri Adi Shankaracharya in 820 CE at Kedarnath reached the Malabar coast only a few years later. It is believed that Kerala began the Malayalam era in 825 CE in his memory.[6] [7] [8] According to Hermann Gundert, Kollam era started as part of erecting a new Shiva Temple in Kollam and because of the strictly local and religious background, the other regions did not follow this system at first. Once Kollam port emerged as an important trade center, however, the other principalities also started following the new system of calendar. This theory backs the remarks of Ibn Battuta as well.[9] The Kollam era may also be attributed to the legend of Paraśurāma, an incarnation of Vishnu. It is sometimes divided into cycles of 1,000 years reckoned from 1176 BCE. Thus, 825 CE would have been the first year of the era's third millennium.[10] | |||
| solar | Hindu/ Buddhist | Medieval | Nepal | One of the Hindu calendars | ||
| lunisolar | Buddhist/ Hindu | 9th century | Nepal | A lunisolar Buddhist calendar traditional to Nepal, recognition in Nepal in 2008. | ||
| lunisolar | Bengali | Medieval | Revised in 1987. | |||
| lunisolar | Hindu/Buddhist | Medieval | Thailand | A Buddhist calendar | ||
| fixed (210 days) | Hindu | Bali | ||||
| solar | 10th century | medieval Iceland | Partly inspired by the Julian calendar and partly by older Germanic calendar traditions. Leap week calendar based on a year of 364 days. | |||
| lunisolar | Chinese-derived | 10th century | Vietnam | After Vietnam regained independence following the third Chinese domination of Vietnam, the following dynasties established their own calendars based on Chinese prototypes, and every subsequent dynasty had appointed officers to man and create the calendar to be used in the realm. | ||
| solar | Iranian | 1079 | Seljuk Sultanate | A calendar reform commissioned by Sultan Jalal al-Din Malik Shah I | ||
| lunisolar | Babylonian/Seleucid-derived | 11th/12th century | Recorded 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. | |||
| lunisolar | Buddhist/Chinese-derived | 13th century | Tibet | The Kalacakra, a Buddhist calendar introduced in 13th-century Tibet | ||
| Seasonal Instruction | solar | 1281 | China | Based on a solar year of 365.2425 (equal to the Gregorian year) | ||
| solar | Julian | 13th century | Sweden | A 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 (ß) | solar | In use 1368-1644 | ||||
| lunisolar | Pre-Columbian | 15th century | ||||
| lunisolar | Pre-Columbian | 15th century | Complex 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. | |||
| lunisolar | 16th century | Southeast Asia | ||||
| solar | Julian-derived | 1582 | worldwide | Introduced as a reform of the Julian calendar in the Roman Catholic church, since the 20th century in de facto use worldwide. | ||
| lunar | Islamic influenced | 1633 | Java | Based on the Hindu calendar using the Saka era (78 CE), but changed by Sultan Agung of Mataram its method of counting of years from solar years to lunar years as per the Islamic calendar. | ||
| Seasonal Constitution | solar | 1645 | China | First Chinese Calendar to use the true motion of the sun. | ||
| solar | Julian-derived | 1700 | Sweden | Part of the controversy surrounding the adoption of the Gregorian calendar, in use 1700–1712. | ||
| solar | Julian-derived | 1740 | Astronomy | A 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. | ||
| solar | Gregorian | 1793 | First French Republic | In use in revolutionary France 1793 to 1805. | ||
| solar | Gregorian | 1745 | — | Universal Georgian Calendar proposed by Hugh Jones | ||
| solar | Julian | 1839 | Julian calendar using the Hijri era introduced in the Ottoman Empire. | |||
| Solar | Gregorian | 1849 | — | Solar calendar with 13 months of 28 days. | ||
| solar | 1873 | Baháʼí | Uses a year of 19 months of 19 days each and a 1844 era. Also known as the "Baháʼí Calendar" or the "Wondrous Calendar". | |||
| solar | Gregorian | 1888 | Thailand | The Gregorian calendar but using the Buddhist Era (543 BC) | ||
| solar | Gregorian | 1900 | — | Gregorian calendar with four 91-day quarters of 13 weeks | ||
| solar | Gregorian | 1902 | — | A "perpetual calendar" with a year of 13 months of 28 days each. | ||
| solar | Gregorian | 1912 | Republic of China | Months and days use the Gregorian calendar, introduced in China in 1912. | ||
| solar | Julian-derived | 1923 | some Orthodox churches | currently synchronized with the Gregorian calendar, but different leap rule and cycle (900 years), also called Meletian calendar or Milanković calendar, after Serbian scientist Milutin Milanković who developed it. | ||
| solar | Iranian/Islamic | 1925 | Iran, Afghanistan | New 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 (reign of Cyrus the Great), but was reverted to the Hijri era after the Iranian Revolution. | ||
| solar | Gregorian | 1926 | Italy | Epoch is 29 October 1922; in use from 1926 - 1943 | ||
| solar | Gregorian | 1929 | Soviet Union | Gregorian calendar with 5- and 6-day weeks, used during 1929 to 1940. | ||
| solar | Gregorian | 1930 | — | Perpetual calendar with 1–2 off-week days, preferred and almost adopted by the United Nations in 1950s | ||
| solar | Gregorian | 1930 | — | Leap week calendar | ||
| solar | Gregorian | 1949 | — | Absurdist variant of the Gregorian calendar by Alfred Jarry. | ||
| solar | Gregorian-derived | 1957 | Republic of India | Gregorian calendar with months based in traditional Hindu calendars and numbering years based on the Saka era (AD 78). | ||
| solar | Babylonian | 1950s | Solar calendar with an "Assyrian era" of 4750 BC, introduced in Assyrian nationalism in the 1950s | |||
| solar | Gregorian | 1963 | Calendar invented in the context of the absurdist or parody religion of Discordianism, Gregorian calendar variant with a year consisting of five 73-day seasons. | |||
| solar | Gregorian | 1973 | — | Divides the year into four seasons. | ||
| solar | Mayan | 1990 | 13 months of 28 days each, synchronized with the Maya 260-day Tzolkin, calibrated to the Chilam Balam timing systems | |||
| Tranquility Calendar | solar | Gregorian | 1989 | — | Modification of the International Fixed Calendar, starting with Apollo 11 Moon landing on 20 July 1969[11] | |
| solar | Gregorian | 1993 | — | The Gregorian calendar with the era shifted by 10,000 years. | ||
| solar | Gregorian | 1997 | Gregorian calendar with the era 1912 (birth of Kim Il-sung) | |||
| solar | Sikh | 1789 | Sikh Calendar numbering years based on the era 1469 (birth of Guru Nanak) | |||
| solar | Gregorian | 2004 | — | Leap week calendar with 4:5:4 weeks per month | ||
| solar | Gregorian | 2004 | — | Leap week calendar with 30:30:31 days per month, revised in 2011 and 2016 | ||
| solar | Indigenous West African | 2009 | Proposal[12] based in Igbo tradition dating back to 13th century, 13 lunar months of 28 days divided into seven 4-day periods, plus leap days. | |||
| Lunisolar | Hindu | India/Nepal | The Vira Nirvana Samvat (era) is a calendar era beginning on 7 October 527 BCE. It commemorates the Nirvana of Lord Mahaviraswami, the 24th Jain Tirthankara. This is one of the oldest system of chronological reckoning which is still used in India. |
Regional or historical names for lunations or Julian/Gregorian months
| Tradition | culture | comments |
|---|---|---|
| Medieval records of Germanic names of lunar months later equated with the Julian months. | ||
| reconstructed medieval Berber-language names of the Julian months used in pre-Islamic (Roman era) North Africa | ||
| Lithuanian names for the Gregorian months and days of the week, officially recognized in 1918. | ||
| Thirteen names of lunar months recorded in the 19th century. | ||
| Turkmen names officially adopted in 2002 following Ruhnama by president-for-life Saparmurat Niyazov. | ||
| A great variety of regional month names in Ancient Greece, mostly attested in the 2nd century BC. | ||
| Local month names in various Slavic countries, based on weather patterns and conditions, and agricultural activities that take place in each respective month. | ||
| Traditional names for the twelve months of the Gregorian calendar, which are usually used by the Romanian Orthodox Church. | ||
| Tradition | week length | comments |
|---|---|---|
| various | ||
| 4 days | The traditional Igbo week consists of four market days: eke, orie, afor, and nkwo. | |
| 4 days | Traditional Yoruba calendar | |
| 5 days | For traditional markets in Korea, for example, the market is open every five days. | |
| Java - (Pasaran) | 5 days | |
| 5 days | ||
| 6 days | A traditional "six-day week" which combined with the Gregorian seven-day week gave rise to a 42-day cycle. | |
| 8 days | The Roman nundinal cycle. | |
| 8 days | ||
| 8 days | reconstructed.[13] [14] | |
| Baltic | 9 days | Linguistic reconstruction; the Gediminas Sceptre indicated that a week lasted for nine days during King Gediminas' reign. |
| 10 days | ||
| 10 days | The 10-day period was known as decans or decades | |
| 10 days | ||
| 13 days | Trecena, division of the Tonalpohualli 260-day period | |