Lunisolar calendar

A lunisolar calendar is a calendar in many cultures whose date indicates both the Moon phase and the time of the solar year. If the solar year is defined as a tropical year, then a lunisolar calendar will give an indication of the season;if it is taken as a sidereal year, then the calendar will predict the constellation near which the full moon may occur.As with all calendars which divide the year into months there is an additional requirement that the year have a whole number of months. In this case ordinary years consist of twelve months but every second or third year is an embolismic year, which adds a thirteenth intercalary, embolismic, or leap month. A lunisolar calendar is a calendar in many cultures whose date indicates both the Moon phase and the time of the solar year. If the solar year is defined as a tropical year, then a lunisolar calendar will give an indication of the season;if it is taken as a sidereal year, then the calendar will predict the constellation near which the full moon may occur.As with all calendars which divide the year into months there is an additional requirement that the year have a whole number of months. In this case ordinary years consist of twelve months but every second or third year is an embolismic year, which adds a thirteenth intercalary, embolismic, or leap month. The Hebrew, Jain, Buddhist, Hindu and Kurdish as well as the traditional Burmese, Chinese, Japanese, Tibetan, Vietnamese, Mongolian and Korean calendars (in the east Asian cultural sphere), plus the ancient Hellenic, Coligny, and Babylonian calendars are all lunisolar. Also, some of the ancient pre-Islamic calendars in south Arabia followed a lunisolar system. The Chinese, Coligny andHebrew lunisolar calendars track more or less the tropical year whereas the Buddhist and Hindu lunisolar calendars track the sidereal year. Therefore, the first three give an idea of the seasons whereas the last two give an idea of the position among the constellations of the full moon. The Tibetan calendar was influenced by both the Chinese and Buddhist calendars. The Germanic peoples also used a lunisolar calendar before their conversion to Christianity. The Islamic calendar is lunar, but not a lunisolar calendar because its date is not related to the Sun. The civil versions of the Julian and Gregorian calendars are solar, because their dates do not indicate the Moon phase — however, both the Gregorian and Julian calendars include undated lunar calendars that allow them to calculate the Christian celebration of Easter, so both are lunisolar calendars in that respect.