Lunisolar Calendar

A lunisolar calendar is a type of calendar that combines lunar and solar cycles to keep track of time. The lunar cycle is based on the phases of the moon, which lasts approximately 29.5 days, while the solar cycle is based on the Earth's orbit around the sun, which lasts about 365.25 days.

In a lunisolar calendar, the months are based on the lunar cycle, while the years are synchronized with the solar cycle by adding extra months or days at regular intervals. This allows the calendar to stay in alignment with the changing seasons, which is important for agricultural and religious purposes.

One of the most well-known lunisolar calendars is the Hebrew calendar, which is used to determine the dates of Jewish holidays. Another example is the Chinese calendar, which is based on the lunar phases and intercalates extra months to stay in sync with the solar year.

Lunisolar calendars are used by various cultures and religions around the world and have been in use for thousands of years.