Calendar with Lunar Cycle

Calendar based on lunar cycles is called lunar calendar. Many calendars with lunar cycles have been used in history, each with its own specifications. But, the only true calendar that is based on lunar cycles and widely used is undoubtedly the Islamic Hijri calendar. They Islamic hijri lunar calendar consists of 12 months. It is based on the drifts of moon that is with the appearance of new moon the month starts. Generally, each Islamic lunar year drifts 11 to 12 days from the solar year and matches the solar year after 33 years. Apart from the Islamic Hijri calendar other lunar calendars can more of be called as lunisolar calendar. Lunisolar calendars generally add some intercalary months to catch up with the solar year.

Different lunar calendars have different opinion regarding the start of month. In Chinese lunar calendars, month is generally started with the appearance of new moon. On the contrary many Hindu lunar take the full moon as the indicator of the new month. There are generally 29.530589 days in lunar calendar. It means there are alternatively 29 and 30 days in a lunar month which are named as hollow and full month respectively.