Different methods used to track time, such as the Gregorian calendar, Julian calendar, and lunar calendars.
Lunar Calendar: A type of calendar used in many cultures that is based on the phases of the moon.
Solar Calendar: A calendar based on the position of the sun in the sky, typically using the equinoxes and solstices as reference points.
Lunisolar Calendar: A calendar that combines lunar and solar cycles to track both the phases of the moon and the changing seasons.
Julian Calendar: A calendar introduced by Julius Caesar in 45 BCE that was used in the Western world for more than 1500 years.
Gregorian Calendar: The calendar currently used in most of the world, which was introduced by Pope Gregory XIII in 1582 to correct for the inaccuracies of the Julian calendar.
Islamic Calendar: A lunar calendar used in the Islamic world that begins with the year of the Hijra, when the prophet Muhammad migrated from Mecca to Medina.
Buddhist Calendar: A lunisolar calendar used in various Buddhist traditions that is based on the cycles of the moon and the movement of the sun.
Hebrew Calendar: A lunisolar calendar used in the Jewish tradition that incorporates both the lunar cycle and the solar year.
Chinese Calendar: A lunisolar calendar used in China that is based on a combination of the cycles of the sun and the moon, and is used for religious and cultural purposes as well as for determining astrological signs.
Mayan Calendar: A complex system of calendars used by the ancient Maya civilization, which included a solar calendar, a 260-day sacred calendar, and a long-count calendar that tracked time over thousands of years.
Aztec Calendar: A complex system of calendars used by the Aztecs and other Mesoamerican civilizations that combined solar and ritual cycles to track time and religious events.
Zodiac: A system of astrological signs based on the position of the sun in the sky that is used in many cultures to determine personality traits and predict future events.
Chronology: The study of time and the ordering of events in history, including the use of calendars and other systems of measurement.
Gregorian calendar: This is the most widely used calendar system that is solar-based and has 365 days with a leap year occurrence of every four years.
Julian calendar: This is a solar-based calendar that was introduced by Julius Caesar in 46 BC in the Roman Empire. It has 365.25 days with a leap year occurrence of every four years.
Islamic calendar (Hijri calendar): This is a lunar-based calendar that has twelve months and 354 or 355 days. It is based on the sighting of the moon.
Hebrew calendar (Jewish calendar): This calendar is based on both solar and lunar cycles and has 12 months that begin with the sighting of the new moon.
Chinese calendar: This calendar is a lunisolar calendar that is used in China and other parts of East Asia. It is based on the cycles of the moon and the sun.
Hindu calendar: This is a lunisolar calendar that is used in India and is based on the position of the moon and the sun.
Persian calendar (Solar Hejri calendar): This is a solar calendar that is used in Iran and is based on the true solar year.
Thai calendar: This is a lunisolar calendar that is used in Thailand and is based on the cycles of the moon.
Ethiopian calendar: This is a solar calendar that is used in Ethiopia and has twelve months with 30 days each and a thirteenth month with five or six days.
Maya calendar: This calendar was used by the Maya civilization in Mesoamerica and is based on the cycles of the moon and the sun. It has several cycles of different lengths.
Coptic calendar: This is a lunar calendar that is used by the Coptic Orthodox Church in Egypt and has 13 months with 12 of them having 30 days and a thirteenth month having five or six days.
Aztec calendar: This is a calendar system that was used by the Aztec civilization in Mexico and is based on a combination of solar and ritual cycles.
Bahá'í calendar: This is a solar-based calendar that is used by the Bahá'í Faith and has 19 months with 19 days each.
Zoroastrian calendar: This is a solar-based calendar that is used by the Zoroastrian religion and has 12 months with 30 days each and a thirteenth month with five or six days.
French Revolutionary calendar: This is a calendar system that was used by the French Republic during the French Revolution and has 12 months with 30 days each and five or six extra days at the end of the year.
Balinese Pawukon calendar: This is a calendar system that is used in Bali, Indonesia and is based on a cycle of 210 days.
Julian Day: This is a system that assigns a unique number to each day that has elapsed since the beginning of the Julian period (January 1, 4713 BC).
Discordian calendar: This is a calendar system that is used by followers of the Discordian religion and has five seasons with 73 days each.