Calendar Systems of the World
AnyCalendar supports 15 calendar systems spanning thousands of years of human timekeeping. Browse each system below, or convert a date between any of them.
Gregorian
The Gregorian calendar is the most widely used civil calendar in the world. Introduced by Pope Gregory XIII in 1582 as a reform of the Julian calendar, it corrected the drift in the date of Easter by refining the leap year rule. It is a solar calendar with 365 days in a common year and 366 in a leap year.
Used in: Worldwide
Islamic (Hijri)
The Islamic calendar is a purely lunar calendar consisting of 12 months of 29 or 30 days. It is used to determine Islamic holidays and rituals such as Ramadan and Hajj. Because it is about 11 days shorter than the solar year, its months migrate through all seasons over a 33-year cycle.
Used in: Middle East, North Africa, Southeast Asia, Muslim-majority countries
Chinese
The Chinese calendar is a lunisolar calendar that combines lunar months with a solar year through the use of intercalary (leap) months. It has been used for thousands of years to determine traditional Chinese holidays like Lunar New Year and the Mid-Autumn Festival. Each year is associated with one of 12 zodiac animals in a repeating 12-year cycle.
Used in: China, Taiwan, overseas Chinese communities
Indian Civil (Saka)
The Indian National Calendar, also known as the Saka calendar, was adopted in 1957 as the official civil calendar of India alongside the Gregorian calendar. It is a solar calendar with 365 days (366 in leap years) and its epoch is the Saka Era (78 CE). The first month, Chaitra, begins on March 22 (or March 21 in leap years).
Used in: India
Persian (Solar Hijri)
The Solar Hijri calendar is an astronomical solar calendar used as the official calendar in Iran and Afghanistan. It is one of the most accurate calendars in use, with its year beginning on the March equinox as determined by astronomical observation. The calendar was reformed in the 11th century by Omar Khayyam and a panel of astronomers.
Used in: Iran, Afghanistan
Buddhist
The Buddhist calendar is a lunisolar calendar used in mainland Southeast Asian countries. Its year numbering is based on the traditional date of the Buddha's parinibbana (passing), which is 543 years before the common era. While the months follow a lunisolar system, the Thai solar variant is commonly used for civil purposes.
Used in: Thailand, Cambodia, Laos, Myanmar, Sri Lanka
Ethiopian (Ge'ez)
The Ethiopian calendar is the principal calendar used in Ethiopia and Eritrea. It has 12 months of 30 days each plus a 13th month of 5 or 6 days. The calendar is approximately 7 to 8 years behind the Gregorian calendar because it calculates the Annunciation of Jesus differently.
Used in: Ethiopia, Eritrea
Hebrew
The Hebrew calendar is a lunisolar calendar used for Jewish religious observances and as the official calendar of Israel. It features a complex 19-year Metonic cycle with 7 leap years that add an extra month to keep the calendar in sync with the seasons. Months alternate between 29 and 30 days, and the calendar has been used since antiquity.
Used in: Israel, Jewish communities worldwide
Coptic
The Coptic calendar descends from the ancient Egyptian calendar and is used by the Coptic Orthodox Church to determine religious holidays. Like the Ethiopian calendar, it has 12 months of 30 days and a short intercalary month. Its epoch is 284 CE, the Era of the Martyrs, commemorating Diocletian's persecution of Christians in Egypt.
Used in: Egypt (Coptic community)
Julian
The Julian calendar was introduced by Julius Caesar in 46 BCE as a reform of the Roman calendar. It established the 365-day year with a leap day every four years, but its slight overestimate of the solar year caused it to drift by about 13 days relative to the Gregorian calendar. It is still used by some Eastern Orthodox churches to calculate feast days.
Used in: Eastern Orthodox churches, historical usage
Baha'i (Badi)
The Baha'i calendar, also known as the Badi calendar, was created by the Bab and later adopted by Baha'u'llah. It consists of 19 months of 19 days each, plus intercalary days. The year begins on Naw-Ruz (the March equinox), and its epoch is 1844 CE, the year of the Bab's declaration.
Used in: Baha'i communities worldwide
ISO Week Date
The ISO week date system is part of the ISO 8601 standard for representing dates. It defines a year as having either 52 or 53 full weeks, with each week starting on Monday. It is widely used in business, government, and manufacturing for scheduling and fiscal planning.
Used in: International (business, industry, government)
Julian Day Number
The Julian Day Number is a continuous count of days since the beginning of the Julian Period on January 1, 4713 BCE (Julian calendar). It is used primarily in astronomy, chronology, and software to simplify date calculations across different calendar systems. Despite the name, it is unrelated to the Julian calendar.
Used in: International (astronomy, science)
Unix Timestamp
Unix time is a system for tracking time as the number of seconds elapsed since the Unix epoch: midnight UTC on January 1, 1970. It is the standard time representation in Unix, Linux, and most programming languages. It does not account for leap seconds, keeping each day at exactly 86,400 seconds.
Used in: International (computing, software)
Mayan Long Count
The Mayan Long Count calendar is a non-repeating base-20 and base-18 calendar used by pre-Columbian Mesoamerican civilizations. It counts days from a mythological creation date corresponding to August 11, 3114 BCE in the Gregorian calendar. The Long Count rose to popular attention around the 2012 phenomenon, though the calendar itself simply rolled over to a new cycle.
Used in: Historical Mesoamerica (Maya, Aztec civilizations)