calendar-kyuureki.txt

calendar/kyuureki-*
~~~~~~~~~~~~~~~~~~~

These files contain descriptions of Kyuureki (旧暦, Old Style Calendar
of Japan).

* kyuureki-map

Web page:
<https://wiki.suikawiki.org/n/%E6%97%A7%E6%9A%A6%E3%83%87%E3%83%BC%E3%82%BF%E3%83%95%E3%82%A1%E3%82%A4%E3%83%AB>

The |data/calendar/kyuureki-map.txt| file is a date mapping file
<https://manakai.github.io/spec-datetime/#date-mapping-file> from the
Gregorian days
<https://manakai.github.io/spec-datetime/#gregorian-day> serialized as
Gregorian date strings to the Kyuureki days
<https://manakai.github.io/spec-datetime/#kyuureki-day> serialized as
Kyuureki date strings, in the range Kyuureki -0666-01-01 (the first
day of the Kyuureki year -666 = 667BC) - Kyuureki 2100-01-01 (the
first day of the Kyuureki year 2101), inclusive.

Revision history:
<https://wiki.suikawiki.org/n/%E6%97%A7%E6%9A%A6%E3%83%87%E3%83%BC%E3%82%BF%E3%83%95%E3%82%A1%E3%82%A4%E3%83%AB#header-section-%E6%94%B9%E8%A8%82%E5%B1%A5%E6%AD%B4>.

Likewise, the |data/calendar/kyuureki-ryuukyuu-map.txt| file is a date
mapping file from the Gregorian days to the kyuureki days as used in
Okinawa (Ryuukyuu) area of Japan, where Chinese calendar was used in
Ryuukyuu Kingdom days.

The first slots of the file are represented as Gregorian date strings
and the second slots of the file are represented as kyuureki date
strings.

The entries are sorted in the ascending order.

Various existing mapping tables and convertion tools use different
mappings (see kyuureki-diff* files).  These tables adopt mappings from
following sources:

  日本の暦日データベース provided by 国立天文台 of Japan
  20世紀暦
  21世紀暦
  兩千年中西曆轉換 (for Chinese calendar)

The month numbers of year 2033 and 2034 (c.f. 旧暦2033年問題) are
chosen as recommended as the 閏11月 method by 一般社団法人日本カレンダー
暦文化振興協会 (暦文協).

* kyuureki-genten

The |data/calendar/kyuureki-genten.json| file contains some data from
日本暦日原典 (第4版).

The file contains a JSON object with following name/value pairs:

  mapping [object]

    Some of mapping data between Gregorian and kyuureki days from 日本
    暦日原典.  Note that Julian dates in 日本暦日原典 are converted to
    proleptic Gregorian date in this object.  Note also that this
    object only contains a few interesting mapping data.  Names are
    Gregorian date strings and values are corresponding kyuureki date
    strings.

  notes [notes-object]

    List of annotations in the table of 日本暦日原典.

* kyuureki-shoki-genten

The |data/calendar/kyuureki-shoki-genten.json| file contains some data
from 日本書紀暦日原典 (1978).

The file contains a JSON object with following name/value pairs:

  mapping [object]

    Some of mapping data between Gregorian and kyuureki days from 日本
    書紀暦日原典.  Note also that this object contains only a few
    mapping data.  Names are Gregorian date strings and values are
    corresponding kyuureki date strings.

* kyuureki-sources.json

The |data/calendar/kyuureki-sources.json| file contains some data from
various kyuureki tables and studies.

The file contains a JSON object with following name/value pairs, where
names identify sources and values are JSON objects containing
following name/value pair, describing the corresponding sources:

  map [object]

    Some of mapping data between Gregorian and Kyuureki days from the
    source.  Note also that this object contains only a few mapping
    data.  Names are kyuureki date strings and values are
    corresponding Gregorian date strings.

  notes [notes-object]

    List of annotations for the source.

  partial [boolean]

    A [boolean] true value, which represents that the |map| does not
    contain all dates in the range.

There are following top-level keys, identifying sources:

  c/n/  <https://wiki.suikawiki.org/n/%E8%BE%B2%E6%9A%A6#anchor-/n/>
  j/n/  <https://wiki.suikawiki.org/n/%E6%97%A7%E6%9A%A6$20368#anchor-/n/>
  j245-actual "便覧" from <https://wiki.suikawiki.org/n/%E6%97%A7%E6%9A%A6$20368#anchor-245>
  j245-computed "推算" from <https://wiki.suikawiki.org/n/%E6%97%A7%E6%9A%A6$20368#anchor-245>

* kyuureki-diff*

The |data/calendar/kyuureki-diff.json| file contains differences of
various existing Kyuureki mapping tables.

The |data/calendar/kyuureki-diff-all.html| and
|data/calendar/kyuureki-diff-tables.html| files are its HTML table
visualizations.

See SuikaWiki:旧暦 for more information on data sources.

* Data types

Gregorian date string
<https://manakai.github.io/spec-datetime/#gregorian-date-string>

Kyuureki date string
<https://manakai.github.io/spec-datetime/#kyuureki-date-string>.

Type [notes-object] represents a JSON object containing (existence of)
notes from the relevant source document.  Names are kyuureki date
strings and values are objects with following name/value pairs:

  has_note [boolean]

    Whether there is some note for the date or not.

  might_be_advanced [boolean]

    進朔の可能性が強いが日本暦日原典では進朔していない。

  misc_note [boolean]

    Any other annotation.

  use_computed_value [boolean]

    議論の余地があるものの、日本暦日原典では原則通りの計算値を採用して
    いる。

  use_fixed_value [boolean]

    日本暦日原典で計算値でなく修正値を採用している。

  vary_by_algorithm [boolean]

    採用する計算方法により計算値が異なる。

* Sources

三正綜覧, 内務省地理局,
<http://www.wul.waseda.ac.jp/kotenseki/html/ni05/ni05_02143/index.html>.

日本書紀暦日原典, 內田正男, 1978.

日本暦日原典, 内田正男, 1992 (第4版).

20世紀暦 -- 曜日・干支・九星・旧暦・六曜, 日外アソシエーツ編集部.

21世紀暦 -- 曜日・干支・九星・旧暦・六曜, 日外アソシエーツ編集部.

SuikaWiki:旧暦
<https://wiki.suikawiki.org/n/%E6%97%A7%E6%9A%A6$20368>.

中央研究院 兩千年中西曆轉換 <http://sinocal.sinica.edu.tw/>.

* License

You are granted a license to use, reproduce and create derivative
works of these files.

Per CC0 <https://creativecommons.org/publicdomain/zero/1.0/>, to the
extent possible under law, the author of the JSON files and this
document has waived all copyright and related or neighboring rights to
the JSON files and this document.