Changes

==Characteristics of the Chinese calendar==

==Characteristics of the Chinese calendar==

The Chinese calendar, at least by the time it was adopted in Japan, was not an observational one ("There, we can see the new moon, so the month has started."), but a predictive one, based on calculations, as was necessary for a widely-spread out, developed bureaucracy. The calculation methods were revised at various times, both in China and Japan, so not everything below applies to all periods, especially the way of determining intercalary months.

The Chinese calendar, at least by the time it was adopted in Japan, was not an observational one ("There, we can see the new moon, so the month has started."), but a predictive one, based on calculations, as was necessary for a widely-spread out, developed bureaucracy. The calculation methods were revised at various times, both in China and Japan, so not everything below applies to all periods, especially the way of determining intercalary months. Further, as a result of Chinese and Japanese authorities performing their calendrical calculations separately, the Chinese and Japanese calendars often differed historically by a day or several.

The Chinese calendar is a lunar, actually a luni-solar, calendar. The start of the month is determined by the new moon, but the position of the month in the year is determined by the solar year, that is, course of the seasons. One should note that although in the the West seasons are considered to begin on the equinoxes and solstices, in the Chinese calendar, the start of spring (立春) is exactly half-way between the winter solstice and the spring equinox, and similarly for other seasons.

The Chinese calendar is a lunar, actually a luni-solar, calendar. The start of the month is determined by the new moon, but the position of the month in the year is determined by the solar year, that is, course of the seasons. One should note that although in the the West seasons are considered to begin on the equinoxes and solstices, in the Chinese calendar, the start of spring (立春) is exactly half-way between the winter solstice and the spring equinox, and similarly for other seasons.

*Months are either 29 (''Shô no tsuki'' 小の月) or 30 days (''Dai no tsuki'' 大の月) long.  This means that the date 2/30 is possible, whereas 3/31 is not.  Unlike some other calendars, it is  '''not''' the case that a particular month is normally a particular length. There is no way of knowing whether a month is 29 or 30 days long except by looking at the calendar for a particular year. Normally, but frequently not, 29-day and 30-day months alternate.  

*Months are either 29 (''Shô no tsuki'' 小の月) or 30 days (''Dai no tsuki'' 大の月) long.  This means that the date 2/30 is possible, whereas 3/31 is not.  Unlike some other calendars, it is  '''not''' the case that a particular month is normally a particular length. There is no way of knowing whether a month is 29 or 30 days long except by looking at the calendar for a particular year. Normally, but frequently not, 29-day and 30-day months alternate.  

*The calendar also takes into account the solar year. The solar year is divided into twelve periods by twelve solar points (中気　chûki) : the winter solstice, the spring equinox, the sumer solstice, the autumn solstice, and two points between each. <ref> The year is also divided into 24 "solar terms" (節気 ''sekki'') such as the "Great Cold."  These are the 12 chûki plus the 12 points that are half-way between chûki. </ref> The months are numbered according to the solar point that occurs during that month.  For example, the month in which the winter solstice occurs is the 11th month, and the one in which the spring equinox occurs is the 2nd month.

*The calendar also takes into account the solar year. The solar year is divided into twelve periods by twelve solar points (中気　chûki) : the winter solstice, the spring equinox, the sumer solstice, the autumn solstice, and two points between each. <ref> The year is also divided into 24 "solar terms" (節気 ''sekki'') such as the "Great Cold."  These are the 12 chûki plus the 12 points that are half-way between chûki. </ref> The months are numbered according to the solar point that occurs during that month.  For example, the month in which the winter solstice occurs is the 11th month, and the one in which the spring equinox occurs is the 2nd month.

   

   

===Intercalary Months===

===Intercalary Months===

As the solar year is about 365.25 days but 12 lunar months last only about 354, each year the months start about 11 days earlier with respect to the solar calendar (the seasons) as they did the previous year.  In fact, in about two years and eight months, the calendar moves a full month ahead.<ref> The Islamic calendar does not have intercalary months, so any given month changes its season year by year. There is no way of knowing the season of any month except by checking on a chart of that year.</ref> In order to keep the lunar and solar calendar from getting too far apart, as noted in the characteristics above, when the month gets a full month ahead,  the month is given the same number as the preceding month, but is called an "閏 (''uruu'')" month. For example, if there are two "third months," the first is called just "third month," but the next is called the "uruu third month". In this Wiki it is referred to as "'''int. 3'''", for "intercalary 3rd month".  Thus,  1599/3 was followed by 1599/int. 3, which was followed by 1599/4. This type of intercalary month, which can happen any month in the year, is a feature of the Chinese-type luni-solar calendar.

As the solar year is about 365.25 days but 12 lunar months last only about 354, each year the months start about 11 days earlier with respect to the solar calendar (the seasons) as they did the previous year.  In fact, in about two years and eight months, the calendar moves a full month ahead.<ref> The Islamic calendar does not have intercalary months, so any given month changes its season year by year. There is no way of knowing the season of any month except by checking on a chart of that year.</ref> In order to keep the lunar and solar calendar from getting too far apart, as noted in the characteristics above, when a month finishes too soon,  the month is given the same number as the preceding month, but is called an "閏 (''uruu'')" month. For example, if there are two "third months," the first is called just "third month," but the next is called the "uruu third month". In this Wiki it is referred to as "'''int. 3'''", for "intercalary 3rd month".  Thus,  1599/3 was followed by 1599/int. 3, which was followed by 1599/4. This type of intercalary month, which can happen any month in the year, is a feature of the Chinese-type luni-solar calendar.

==Calculation Website ==

==Calculation Website ==

Unlike conversions between era years and Western years, which is a fairly easy calculation (see [[Year dates]] and [[Japanese Eras]]), conversion between the Western and Chinese calendar can only be done using a monthly table based on historical documents. One table is Tuchihashi's.  However, now there are several websites that provide calculators which look up dates.  One is the following:

Unlike conversions between era years and Western years, which is a fairly easy calculation (see [[Year dates]] and [[Japanese Eras]]), conversion between the Western and Chinese calendar can only be done using a monthly table based on historical documents. One table is Tuchihashi's.  However, now there are several websites that provide calculators which look up dates.  One is the following:

http://www.uni-tuebingen.de/geschichte-japans/nengo_calc.htm which will give the Western year for the Japanese date.

http://web.me.com/meyer.eva/www.yukikurete.de/nengo_calc.htm which will give the Western year for the Japanese date.

Here are several notes on its use:

Here are several notes on its use:

*Before entering the month and day, the Western date shown is that of New Year Day of the Japanese year.

*Before entering the month and day, the Western date shown is that of New Year Day of the Japanese year.

*'''For dates Tenshô 10/9/18 (Oct. 4, 1582) and before, dates are in the Julian calendar, but from the next day,  Tenshô 10/9/19 (Oct. 15, 1582) the dates are the Gregorian calendar.'''

*'''For dates Tenshô 10/9/18 (Oct. 4, 1582) and before, dates are in the Julian calendar, but from the next day,  Tenshô 10/9/19 (Oct. 15, 1582) the dates are the Gregorian calendar.''' This change in the western calendar means you cannot just blindly use the program; you need to know which calendar to use for your western date.<ref>Catholic countries in Europe used the Gregorian immediately; some of Holland used it soon; the English changed in 1752; and Russia in 1918. Because of the distance from Europe, the Jesuits in Japan probably heard about the change in July 1585.

 

*From 1873 on, the Japanese dates are the Gregorian calendar.

*From 1873 on, the Japanese dates are the Gregorian calendar.

==References==

==References==

*[[Kojien Dictionary|''Kôjien Dictionary'']]

*[[Kojien Dictionary|''Kôjien Dictionary'']]

*http://www.uni-tuebingen.de/geschichte-japans/nengo_calc.htm

*http://web.me.com/meyer.eva/www.yukikurete.de/nengo_calc.htm

 

[[Category:Resource Articles]]

[[Category:Resource Articles]]