Lunar (calendar)
A lunar calendar is a type of calendar that is based on the cycles of the Moon, with months typically beginning on the new moon. This type of calendar has been used by many cultures throughout history, including the ancient Chinese, Islamic, and Hebrew calendars. The lunar calendar is often used to determine important dates and events, such as Ritual practices and Cycle of life celebrations. In a lunar calendar, the months are usually either 29 or 30 days long, depending on the timing of the lunar cycle. This can result in a calendar year that is approximately 354 days long, which is about 11 days shorter than a Solar year. To account for this discrepancy, some lunar calendars insert an extra month every few years, a process known as Interpolation.