Lunisolar calendar

A lunisolar calendar (Latin luna, moon ' and sol ' sun ' ) or bound Lunar Calendar Lunar Calendar contains as any as calendar months primarily 12 lunar months. To approach the solar year, a thirteenth lunar month is turned on an average of all not quite three years.

Purpose of the lunisolar calendar

The older calendars were lunar calendars, because they in fact -oriented phases of the moon at certain observable celestial phenomena. For a solar calendar, the much more difficult festzustellenden sun phases, such as the equinoxes or solstices which must be known

A pure lunar calendar has no binding to the solar year and the seasons. He shifts by about eleven days in each solar year backwards. A lunisolar calendar, however, creates an approximate alignment with the seasons, determine the religious ( seasonal festival dates ) and the economic ( sowing and harvesting dates ) life. It follows the solar year with a maximum deviation of ± 2 weeks.

Astronomical Foundations

The long-term synchronization in a lunisolar between months and years, every 19 years possible, because 19 solar years are equal in length to 235 lunar months in a good approximation. This equated with 6940 days period is the Metonic cycle, the resulting cycle of Meton cycle.

When it turned out that 6940 days about a quarter - day are too much for 19 solar years, the period was increased to four times the duration and this equated to 27,759 days. This resulted in the Kallippische period is the Kallippischen cycle basis.

In lunisolar calendars, where the average calendar year is held by a leap day every four years at 365.25 days, which divided by four Kallippische period is applicable. He is the corrected Meton period to 6939.75 days ( 6939.75 ÷ 19 = 365.25 ).

Construction of a lunisolar calendar

It is obvious that since the lunisolar calendar was developed from a lunar calendar, its construction is based on this.

Calendar months are still either full months of 30 days or hollow months of 29 days. The previous lunar calendar -year to 12 months each and 354 days remain ( with leap day to 355 days ) than get nasty calendar year, to be supplemented by occasional switching years. The latter is attached to a 13 - month calendar.

The solution pattern was described in ancient times as follows: Analogous to the Metonic cycle are 19 calendar years from 235 calendar months. 110 of them are hollow months, 125 are full months. This results in 6940 days, the length of the Metonic cycle.

In which composition formed therefrom in ancient calendar years, is not known. The following design could have been possible:

8 years common to each 6 hollow and 6 full months = 48 months hollow and 48 full months ( 354 days each ) 4 common years each with 5 hollow and seven full months = 20 hollow months and 28 full months ( 355 days each, with switching - day adaptation to the lunar year ) 7 leap -year to 6 per hollow and seven full months = 42 hollow months and 49 full months ( 384 days each )

This construction is in the Jewish calendar recognizable, although there happen with 353, 383 and 385 days because of religious traditions, even years. The for antiquity also not traditional order of the switching - years consists in the Jewish calendar from years 3, 6, 8, 11, 14, 17 and 19

There is also an ancient description, do not follow lawful according to which hollow and full months: All 235 months are recognized as full months. All 63 days but omitted one day ( off). This happened in the 6940- day period almost regularly 110 times, thereby indirectly from full months hollow months. Only the failing day is usually not the 30th day of a full month. It is believed that this complex control is applied only in an astronomical, but not in a middle calendar.

In a Kallippischen lunisolar calendar followed by three 19 -year periods, each 6940 days, a 19 -year period to 6,939 days in the scheme described in relation to the account for a day. Also at this detail is not known.

The difficulties in calculating the date of Easter stem from the fact that unlike the Jewish calendar neither Julian nor the Gregorian calendar is lunisolar. To determine the Easter determining spring full moon, a calendar with months bill is to make a Lunar Calendar. One first forms as there years per 354 days. If the 13th Full Moon falls before March 22, the year shall be extended by a lunar calendar month ( moon jump). This results in a Metonic period seven times. Six moon jumps are provided with 30 days, the seventh of 29 days. Because of the Julian calendar every four years added leap day with a share of 4.75 days to 19 years also increases the lunar calendar months, is the balance for 19 years:

19,354 days days 29 days 6:30 4.75 days = 6939.75 days = corrected Meton period

The three change in 400 years omitted in the Gregorian calendar leap day is not the case. The above balance remains, the " lost days " move the calculated day of the Spring full moon indirectly (solar equation).

Applications of a lunisolar calendar

The lunisolar calendars include the Tibetan, Chinese (and other East Asian calendars as the Japanese until 1872 ), Greek, Roman ( until the introduction of the Julian calendar, 46 BC) and Jewish calendar. Most people, however, use either pure lunar or solar calendar.