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3afbc435 | 1 | ;;; cal-china.el --- calendar functions for the Chinese calendar |
0808d911 | 2 | |
4785bf2c GM |
3 | ;; Copyright (C) 1995, 1997, 2001, 2002, 2003, 2004, 2005, 2006, 2007, |
4 | ;; 2008 Free Software Foundation, Inc. | |
0808d911 ER |
5 | |
6 | ;; Author: Edward M. Reingold <reingold@cs.uiuc.edu> | |
dbfca9c4 | 7 | ;; Maintainer: Glenn Morris <rgm@gnu.org> |
0808d911 ER |
8 | ;; Keywords: calendar |
9 | ;; Human-Keywords: Chinese calendar, calendar, holidays, diary | |
10 | ||
11 | ;; This file is part of GNU Emacs. | |
12 | ||
13 | ;; GNU Emacs is free software; you can redistribute it and/or modify | |
14 | ;; it under the terms of the GNU General Public License as published by | |
075969b4 | 15 | ;; the Free Software Foundation; either version 3, or (at your option) |
0808d911 ER |
16 | ;; any later version. |
17 | ||
18 | ;; GNU Emacs is distributed in the hope that it will be useful, | |
19 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
20 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
21 | ;; GNU General Public License for more details. | |
22 | ||
23 | ;; You should have received a copy of the GNU General Public License | |
b578f267 | 24 | ;; along with GNU Emacs; see the file COPYING. If not, write to the |
3a35cf56 LK |
25 | ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, |
26 | ;; Boston, MA 02110-1301, USA. | |
0808d911 ER |
27 | |
28 | ;;; Commentary: | |
29 | ||
30 | ;; This collection of functions implements the features of calendar.el, | |
0031509c ER |
31 | ;; diary.el, and holidays.el that deal with the Chinese calendar. The rules |
32 | ;; used for the Chinese calendar are those of Baolin Liu (see L. E. Doggett's | |
33 | ;; article "Calendars" in the Explanatory Supplement to the Astronomical | |
34 | ;; Almanac, second edition, 1992) for the calendar as revised at the beginning | |
67d80173 ER |
35 | ;; of the Qing dynasty in 1644. The nature of the astronomical calculations |
36 | ;; is such that precise calculations cannot be made without great expense in | |
37 | ;; time, so that the calendars produced may not agree perfectly with published | |
38 | ;; tables--but no two pairs of published tables agree perfectly either! Liu's | |
39 | ;; rules produce a calendar for 2033 which is not accepted by all authorities. | |
40 | ;; The date of Chinese New Year is correct from 1644-2051. | |
0031509c | 41 | |
a96a5fca | 42 | ;; Technical details of all the calendrical calculations can be found in |
fffaba77 PE |
43 | ;; ``Calendrical Calculations: The Millennium Edition'' by Edward M. Reingold |
44 | ;; and Nachum Dershowitz, Cambridge University Press (2001). | |
a96a5fca | 45 | |
465323b6 GM |
46 | ;; Note to maintainers: |
47 | ;; Use `chinese-year-cache-init' every few years to recenter the default | |
48 | ;; value of `chinese-year-cache'. | |
0808d911 | 49 | |
465323b6 | 50 | ;;; Code: |
0b0f8fa4 | 51 | |
0808d911 ER |
52 | (require 'lunar) |
53 | ||
bfcb5172 GM |
54 | (defgroup chinese-calendar nil |
55 | "Chinese calendar support." | |
56 | :group 'calendar) | |
00e3e480 | 57 | |
a1506d29 | 58 | (defcustom chinese-calendar-time-zone |
0808d911 ER |
59 | '(if (< year 1928) |
60 | (+ 465 (/ 40.0 60.0)) | |
61 | 480) | |
67a9fd0d | 62 | "Minutes difference between local standard time for Chinese calendar and UTC. |
465323b6 GM |
63 | Default is for Beijing. This is an expression in `year' since it changed at |
64 | 1928-01-01 00:00:00 from UT+7:45:40 to UT+8." | |
9e935048 | 65 | :type 'sexp |
8db540c5 | 66 | :group 'chinese-calendar) |
0808d911 | 67 | |
8db540c5 | 68 | (defcustom chinese-calendar-location-name "Beijing" |
08f7d912 | 69 | "Name of location used for calculation of Chinese calendar." |
8db540c5 RS |
70 | :type 'string |
71 | :group 'chinese-calendar) | |
0808d911 | 72 | |
8db540c5 | 73 | (defcustom chinese-calendar-daylight-time-offset 0 |
4785bf2c GM |
74 | ;; The correct value is as follows, but the Chinese calendrical |
75 | ;; authorities do NOT use DST in determining astronomical events: | |
76 | ;; 60 | |
67a9fd0d GM |
77 | "Minutes difference between daylight saving and standard time. |
78 | Default is for no daylight saving time." | |
8db540c5 RS |
79 | :type 'integer |
80 | :group 'chinese-calendar) | |
0808d911 | 81 | |
8db540c5 | 82 | (defcustom chinese-calendar-standard-time-zone-name |
0808d911 ER |
83 | '(if (< year 1928) |
84 | "PMT" | |
85 | "CST") | |
08f7d912 | 86 | "Abbreviated name of standard time zone used for Chinese calendar. |
9e935048 RS |
87 | This is an expression depending on `year' because it changed |
88 | at 1928-01-01 00:00:00 from `PMT' to `CST'." | |
89 | :type 'sexp | |
8db540c5 | 90 | :group 'chinese-calendar) |
0808d911 | 91 | |
8db540c5 | 92 | (defcustom chinese-calendar-daylight-time-zone-name "CDT" |
08f7d912 | 93 | "Abbreviated name of daylight saving time zone used for Chinese calendar." |
8db540c5 RS |
94 | :type 'string |
95 | :group 'chinese-calendar) | |
0808d911 | 96 | |
8db540c5 | 97 | (defcustom chinese-calendar-daylight-savings-starts nil |
4785bf2c GM |
98 | ;; The correct value is as follows, but the Chinese calendrical |
99 | ;; authorities do NOT use DST in determining astronomical events: | |
100 | ;; '(cond ((< 1986 year) (calendar-nth-named-day 1 0 4 year 10)) | |
101 | ;; ((= 1986 year) '(5 4 1986)) | |
102 | ;; (t nil)) | |
67a9fd0d GM |
103 | "Sexp giving the date on which daylight saving time starts. |
104 | Default is for no daylight saving time. See documentation of | |
8db540c5 RS |
105 | `calendar-daylight-savings-starts'." |
106 | :type 'sexp | |
107 | :group 'chinese-calendar) | |
0808d911 | 108 | |
8db540c5 | 109 | (defcustom chinese-calendar-daylight-savings-ends nil |
4785bf2c GM |
110 | ;; The correct value is as follows, but the Chinese calendrical |
111 | ;; authorities do NOT use DST in determining astronomical events: | |
112 | ;; '(if (<= 1986 year) (calendar-nth-named-day 1 0 9 year 11)) | |
67a9fd0d GM |
113 | "Sexp giving the date on which daylight saving time ends. |
114 | Default is for no daylight saving time. See documentation of | |
8db540c5 RS |
115 | `calendar-daylight-savings-ends'." |
116 | :type 'sexp | |
117 | :group 'chinese-calendar) | |
0808d911 | 118 | |
8db540c5 | 119 | (defcustom chinese-calendar-daylight-savings-starts-time 0 |
67a9fd0d GM |
120 | "Number of minutes after midnight that daylight saving time starts. |
121 | Default is for no daylight saving time." | |
8db540c5 RS |
122 | :type 'integer |
123 | :group 'chinese-calendar) | |
0808d911 | 124 | |
8db540c5 | 125 | (defcustom chinese-calendar-daylight-savings-ends-time 0 |
67a9fd0d GM |
126 | "Number of minutes after midnight that daylight saving time ends. |
127 | Default is for no daylight saving time." | |
8db540c5 RS |
128 | :type 'integer |
129 | :group 'chinese-calendar) | |
0808d911 | 130 | |
a8774f05 | 131 | (defcustom chinese-calendar-celestial-stem |
465323b6 | 132 | ["Jia" "Yi" "Bing" "Ding" "Wu" "Ji" "Geng" "Xin" "Ren" "Gui"] |
a8774f05 GM |
133 | "Prefixes used by `calendar-chinese-sexagesimal-name'." |
134 | :group 'chinese-calendar | |
135 | :type '(vector (string :tag "Jia") | |
136 | (string :tag "Yi") | |
137 | (string :tag "Bing") | |
138 | (string :tag "Ding") | |
139 | (string :tag "Wu") | |
140 | (string :tag "Ji") | |
141 | (string :tag "Geng") | |
142 | (string :tag "Xin") | |
143 | (string :tag "Ren") | |
144 | (string :tag "Gui"))) | |
145 | ||
146 | (defcustom chinese-calendar-terrestrial-branch | |
465323b6 | 147 | ["Zi" "Chou" "Yin" "Mao" "Chen" "Si" "Wu" "Wei" "Shen" "You" "Xu" "Hai"] |
a8774f05 GM |
148 | "Suffixes used by `calendar-chinese-sexagesimal-name'." |
149 | :group 'chinese-calendar | |
150 | :type '(vector (string :tag "Zi") | |
151 | (string :tag "Chou") | |
152 | (string :tag "Yin") | |
153 | (string :tag "Mao") | |
154 | (string :tag "Chen") | |
155 | (string :tag "Si") | |
156 | (string :tag "Wu") | |
157 | (string :tag "Wei") | |
158 | (string :tag "Shen") | |
159 | (string :tag "You") | |
160 | (string :tag "Xu") | |
161 | (string :tag "Hai"))) | |
162 | ||
163 | ;;; End of user options. | |
164 | ||
465323b6 GM |
165 | |
166 | (defun calendar-chinese-sexagesimal-name (n) | |
167 | "The N-th name of the Chinese sexagesimal cycle. | |
168 | N congruent to 1 gives the first name, N congruent to 2 gives the second name, | |
169 | ..., N congruent to 60 gives the sixtieth name." | |
170 | (format "%s-%s" | |
171 | (aref chinese-calendar-celestial-stem (% (1- n) 10)) | |
172 | (aref chinese-calendar-terrestrial-branch (% (1- n) 12)))) | |
bfcb5172 | 173 | |
0808d911 | 174 | (defun chinese-zodiac-sign-on-or-after (d) |
67a9fd0d | 175 | "Absolute date of first new Zodiac sign on or after absolute date D. |
0808d911 | 176 | The Zodiac signs begin when the sun's longitude is a multiple of 30 degrees." |
465323b6 GM |
177 | (let* ((year (extract-calendar-year (calendar-gregorian-from-absolute d))) |
178 | (calendar-time-zone (eval chinese-calendar-time-zone)) ; uses year | |
0808d911 ER |
179 | (calendar-daylight-time-offset |
180 | chinese-calendar-daylight-time-offset) | |
181 | (calendar-standard-time-zone-name | |
182 | chinese-calendar-standard-time-zone-name) | |
183 | (calendar-daylight-time-zone-name | |
184 | chinese-calendar-daylight-time-zone-name) | |
185 | (calendar-calendar-daylight-savings-starts | |
186 | chinese-calendar-daylight-savings-starts) | |
187 | (calendar-daylight-savings-ends | |
188 | chinese-calendar-daylight-savings-ends) | |
189 | (calendar-daylight-savings-starts-time | |
190 | chinese-calendar-daylight-savings-starts-time) | |
191 | (calendar-daylight-savings-ends-time | |
192 | chinese-calendar-daylight-savings-ends-time)) | |
193 | (floor | |
194 | (calendar-absolute-from-astro | |
465323b6 | 195 | (solar-date-next-longitude (calendar-astro-from-absolute d) 30))))) |
0808d911 ER |
196 | |
197 | (defun chinese-new-moon-on-or-after (d) | |
67a9fd0d | 198 | "Absolute date of first new moon on or after absolute date D." |
465323b6 | 199 | (let* ((year (extract-calendar-year (calendar-gregorian-from-absolute d))) |
0808d911 ER |
200 | (calendar-time-zone (eval chinese-calendar-time-zone)) |
201 | (calendar-daylight-time-offset | |
202 | chinese-calendar-daylight-time-offset) | |
203 | (calendar-standard-time-zone-name | |
204 | chinese-calendar-standard-time-zone-name) | |
205 | (calendar-daylight-time-zone-name | |
206 | chinese-calendar-daylight-time-zone-name) | |
207 | (calendar-calendar-daylight-savings-starts | |
208 | chinese-calendar-daylight-savings-starts) | |
209 | (calendar-daylight-savings-ends | |
210 | chinese-calendar-daylight-savings-ends) | |
211 | (calendar-daylight-savings-starts-time | |
212 | chinese-calendar-daylight-savings-starts-time) | |
213 | (calendar-daylight-savings-ends-time | |
214 | chinese-calendar-daylight-savings-ends-time)) | |
215 | (floor | |
216 | (calendar-absolute-from-astro | |
465323b6 | 217 | (lunar-new-moon-on-or-after (calendar-astro-from-absolute d)))))) |
0031509c ER |
218 | |
219 | (defun chinese-month-list (start end) | |
220 | "List of starting dates of Chinese months from START to END." | |
221 | (if (<= start end) | |
222 | (let ((new-moon (chinese-new-moon-on-or-after start))) | |
223 | (if (<= new-moon end) | |
00e3e480 ER |
224 | (cons new-moon |
225 | (chinese-month-list (1+ new-moon) end)))))) | |
0031509c | 226 | |
465323b6 GM |
227 | (defun number-chinese-months (list start) |
228 | "Assign month numbers to the lunar months in LIST, starting with START. | |
229 | Numbers are assigned sequentially, START, START+1, ..., 11, with | |
230 | half numbers used for leap months. First and last months of list | |
231 | are never leap months." | |
232 | (when list | |
233 | (cons (list start (car list)) ; first month | |
234 | ;; Remaining months. | |
235 | (if (zerop (- 12 start (length list))) | |
236 | ;; List is too short for a leap month. | |
237 | (number-chinese-months (cdr list) (1+ start)) | |
238 | (if (and (cddr list) ; at least two more months... | |
706531d9 | 239 | (<= (nth 2 list) |
465323b6 GM |
240 | (chinese-zodiac-sign-on-or-after (cadr list)))) |
241 | ;; Next month is a leap month. | |
242 | (cons (list (+ start 0.5) (cadr list)) | |
243 | (number-chinese-months (cddr list) (1+ start))) | |
244 | ;; Next month is not a leap month. | |
245 | (number-chinese-months (cdr list) (1+ start))))))) | |
246 | ||
0031509c ER |
247 | (defun compute-chinese-year (y) |
248 | "Compute the structure of the Chinese year for Gregorian year Y. | |
00e3e480 | 249 | The result is a list of pairs (i d), where month i begins on absolute date d, |
0031509c ER |
250 | of the Chinese months from the Chinese month following the solstice in |
251 | Gregorian year Y-1 to the Chinese month of the solstice of Gregorian year Y." | |
252 | (let* ((next-solstice (chinese-zodiac-sign-on-or-after | |
253 | (calendar-absolute-from-gregorian | |
254 | (list 12 15 y)))) | |
255 | (list (chinese-month-list (1+ (chinese-zodiac-sign-on-or-after | |
256 | (calendar-absolute-from-gregorian | |
257 | (list 12 15 (1- y))))) | |
67d80173 ER |
258 | next-solstice)) |
259 | (next-sign (chinese-zodiac-sign-on-or-after (car list)))) | |
0031509c | 260 | (if (= (length list) 12) |
4785bf2c | 261 | ;; No room for a leap month, just number them 12, 1, 2, ..., 11. |
00e3e480 | 262 | (cons (list 12 (car list)) |
67d80173 | 263 | (number-chinese-months (cdr list) 1)) |
4785bf2c GM |
264 | ;; Now we can assign numbers to the list for y. |
265 | ;; The first month or two are special. | |
465323b6 | 266 | (if (or (> (car list) next-sign) (>= next-sign (cadr list))) |
4785bf2c | 267 | ;; First month on list is a leap month, second is not. |
00e3e480 | 268 | (append (list (list 11.5 (car list)) |
465323b6 GM |
269 | (list 12 (cadr list))) |
270 | (number-chinese-months (cddr list) 1)) | |
4785bf2c | 271 | ;; First month on list is not a leap month. |
00e3e480 | 272 | (append (list (list 12 (car list))) |
465323b6 GM |
273 | (if (>= (chinese-zodiac-sign-on-or-after (cadr list)) |
274 | (nth 2 list)) | |
4785bf2c | 275 | ;; Second month on list is a leap month. |
465323b6 GM |
276 | (cons (list 12.5 (cadr list)) |
277 | (number-chinese-months (cddr list) 1)) | |
4785bf2c | 278 | ;; Second month on list is not a leap month. |
67d80173 | 279 | (number-chinese-months (cdr list) 1))))))) |
0031509c | 280 | |
465323b6 GM |
281 | (defvar chinese-year-cache |
282 | ;; Maintainers: delete existing value, position point at start of | |
283 | ;; empty line, then call M-: (chinese-year-cache-init N) | |
284 | '((2000 (12 730126) (1 730155) (2 730185) (3 730215) (4 730244) (5 730273) | |
285 | (6 730303) (7 730332) (8 730361) (9 730391) (10 730420) (11 730450)) | |
286 | (2001 (12 730480) (1 730509) (2 730539) (3 730569) (4 730598) (4.5 730628) | |
287 | (5 730657) (6 730687) (7 730716) (8 730745) (9 730775) (10 730804) | |
288 | (11 730834)) | |
289 | (2002 (12 730863) (1 730893) (2 730923) (3 730953) (4 730982) (5 731012) | |
290 | (6 731041) (7 731071) (8 731100) (9 731129) (10 731159) (11 731188)) | |
291 | (2003 (12 731218) (1 731247) (2 731277) (3 731307) (4 731336) (5 731366) | |
292 | (6 731396) (7 731425) (8 731455) (9 731484) (10 731513) (11 731543)) | |
293 | (2004 (12 731572) (1 731602) (2 731631) (2.5 731661) (3 731690) (4 731720) | |
294 | (5 731750) (6 731779) (7 731809) (8 731838) (9 731868) (10 731897) | |
295 | (11 731927)) | |
296 | (2005 (12 731956) (1 731986) (2 732015) (3 732045) (4 732074) (5 732104) | |
297 | (6 732133) (7 732163) (8 732193) (9 732222) (10 732252) (11 732281)) | |
298 | (2006 (12 732311) (1 732340) (2 732370) (3 732399) (4 732429) (5 732458) | |
299 | (6 732488) (7 732517) (7.5 732547) (8 732576) (9 732606) (10 732636) | |
300 | (11 732665)) | |
301 | (2007 (12 732695) (1 732725) (2 732754) (3 732783) (4 732813) (5 732842) | |
302 | (6 732871) (7 732901) (8 732930) (9 732960) (10 732990) (11 733020)) | |
303 | (2008 (12 733049) (1 733079) (2 733109) (3 733138) (4 733167) (5 733197) | |
304 | (6 733226) (7 733255) (8 733285) (9 733314) (10 733344) (11 733374)) | |
305 | (2009 (12 733403) (1 733433) (2 733463) (3 733493) (4 733522) (5 733551) | |
306 | (5.5 733581) (6 733610) (7 733639) (8 733669) (9 733698) (10 733728) | |
307 | (11 733757)) | |
308 | (2010 (12 733787) (1 733817) (2 733847) (3 733876) (4 733906) (5 733935) | |
309 | (6 733965) (7 733994) (8 734023) (9 734053) (10 734082) (11 734112)) | |
310 | (2011 (12 734141) (1 734171) (2 734201) (3 734230) (4 734260) (5 734290) | |
311 | (6 734319) (7 734349) (8 734378) (9 734407) (10 734437) (11 734466)) | |
312 | (2012 (12 734496) (1 734525) (2 734555) (3 734584) (4 734614) (4.5 734644) | |
313 | (5 734673) (6 734703) (7 734732) (8 734762) (9 734791) (10 734821) | |
314 | (11 734850)) | |
315 | (2013 (12 734880) (1 734909) (2 734939) (3 734968) (4 734998) (5 735027) | |
316 | (6 735057) (7 735087) (8 735116) (9 735146) (10 735175) (11 735205)) | |
317 | (2014 (12 735234) (1 735264) (2 735293) (3 735323) (4 735352) (5 735382) | |
318 | (6 735411) (7 735441) (8 735470) (9 735500) (9.5 735530) (10 735559) | |
319 | (11 735589)) | |
320 | (2015 (12 735618) (1 735648) (2 735677) (3 735707) (4 735736) (5 735765) | |
321 | (6 735795) (7 735824) (8 735854) (9 735884) (10 735914) (11 735943)) | |
322 | (2016 (12 735973) (1 736002) (2 736032) (3 736061) (4 736091) (5 736120) | |
323 | (6 736149) (7 736179) (8 736208) (9 736238) (10 736268) (11 736297)) | |
324 | (2017 (12 736327) (1 736357) (2 736386) (3 736416) (4 736445) (5 736475) | |
325 | (6 736504) (6.5 736533) (7 736563) (8 736592) (9 736622) (10 736651) | |
326 | (11 736681)) | |
327 | (2018 (12 736711) (1 736741) (2 736770) (3 736800) (4 736829) (5 736859) | |
328 | (6 736888) (7 736917) (8 736947) (9 736976) (10 737006) (11 737035)) | |
329 | (2019 (12 737065) (1 737095) (2 737125) (3 737154) (4 737184) (5 737213) | |
330 | (6 737243) (7 737272) (8 737301) (9 737331) (10 737360) (11 737389)) | |
331 | (2020 (12 737419) (1 737449) (2 737478) (3 737508) (4 737538) (4.5 737568) | |
332 | (5 737597) (6 737627) (7 737656) (8 737685) (9 737715) (10 737744) | |
333 | (11 737774))) | |
334 | "Alist of Chinese year structures as determined by `chinese-year'. | |
335 | The default can be nil, but some values are precomputed for efficiency.") | |
336 | ||
337 | (defun chinese-year (y) | |
338 | "The structure of the Chinese year for Gregorian year Y. | |
339 | The result is a list of pairs (i d), where month i begins on absolute date d, | |
340 | of the Chinese months from the Chinese month following the solstice in | |
341 | Gregorian year Y-1 to the Chinese month of the solstice of Gregorian year Y. | |
342 | The list is cached in `chinese-year-cache' for further use." | |
343 | (let ((list (cdr (assoc y chinese-year-cache)))) | |
344 | (or list | |
345 | (setq list (compute-chinese-year y) | |
346 | chinese-year-cache (append chinese-year-cache | |
347 | (list (cons y list))))) | |
348 | list)) | |
349 | ||
350 | ;; Maintainer use. | |
351 | (defun chinese-year-cache-init (year) | |
352 | "Insert an initialization value for `chinese-year-cache' after point. | |
353 | Computes values for 10 years either side of YEAR." | |
354 | (setq year (- year 10)) | |
355 | (let (chinese-year-cache end) | |
356 | (save-excursion | |
357 | (insert "'(") | |
358 | (dotimes (n 21) | |
359 | (princ (cons year (compute-chinese-year year)) (current-buffer)) | |
360 | (insert (if (= n 20) ")" "\n")) | |
361 | (setq year (1+ year))) | |
362 | (setq end (point))) | |
363 | (save-excursion | |
364 | ;; fill-column -/+ 5. | |
365 | (while (and (< (point) end) | |
366 | (re-search-forward "^.\\{65,75\\})" end t)) | |
367 | (delete-char 1) | |
368 | (insert "\n"))) | |
369 | (indent-region (point) end))) | |
370 | ||
0808d911 ER |
371 | (defun calendar-absolute-from-chinese (date) |
372 | "The number of days elapsed between the Gregorian date 12/31/1 BC and DATE. | |
465323b6 GM |
373 | DATE is a Chinese date (cycle year month day). The Gregorian date |
374 | Sunday, December 31, 1 BC is imaginary." | |
0808d911 | 375 | (let* ((cycle (car date)) |
465323b6 GM |
376 | (year (cadr date)) |
377 | (month (nth 2 date)) | |
378 | (day (nth 3 date)) | |
4785bf2c GM |
379 | (g-year (+ (* (1- cycle) 60) ; years in prior cycles |
380 | (1- year) ; prior years this cycle | |
381 | -2636))) ; years before absolute date 0 | |
382 | (+ (1- day) ; prior days this month | |
465323b6 GM |
383 | (cadr ; absolute date of start of this month |
384 | (assoc month (append (memq (assoc 1 (chinese-year g-year)) | |
385 | (chinese-year g-year)) | |
386 | (chinese-year (1+ g-year)))))))) | |
0808d911 ER |
387 | |
388 | (defun calendar-chinese-from-absolute (date) | |
389 | "Compute Chinese date (cycle year month day) corresponding to absolute DATE. | |
390 | The absolute date is the number of days elapsed since the (imaginary) | |
391 | Gregorian date Sunday, December 31, 1 BC." | |
0031509c ER |
392 | (let* ((g-year (extract-calendar-year |
393 | (calendar-gregorian-from-absolute date))) | |
00e3e480 | 394 | (c-year (+ g-year 2695)) |
0031509c ER |
395 | (list (append (chinese-year (1- g-year)) |
396 | (chinese-year g-year) | |
397 | (chinese-year (1+ g-year))))) | |
706531d9 | 398 | (while (<= (cadr (cadr list)) date) |
4785bf2c GM |
399 | ;; The first month on the list is in Chinese year c-year. |
400 | ;; Date is on or after start of second month on list... | |
706531d9 | 401 | (if (= 1 (caar (cdr list))) |
4785bf2c | 402 | ;; Second month on list is a new Chinese year... |
00e3e480 | 403 | (setq c-year (1+ c-year))) |
4785bf2c | 404 | ;; ...so first month on list is of no interest. |
0031509c | 405 | (setq list (cdr list))) |
00e3e480 | 406 | (list (/ (1- c-year) 60) |
c97663f6 GM |
407 | ;; Remainder of c-year/60 with 60 instead of 0. |
408 | (1+ (mod (1- c-year) 60)) | |
706531d9 GM |
409 | (caar list) |
410 | (1+ (- date (cadr (car list))))))) | |
0808d911 | 411 | |
465323b6 GM |
412 | ;; Bound in generate-calendar. |
413 | (defvar displayed-month) | |
414 | (defvar displayed-year) | |
415 | ||
1d0c7fdf | 416 | ;;;###holiday-autoload |
0808d911 ER |
417 | (defun holiday-chinese-new-year () |
418 | "Date of Chinese New Year." | |
419 | (let ((m displayed-month) | |
420 | (y displayed-year)) | |
421 | (increment-calendar-month m y 1) | |
422 | (if (< m 5) | |
423 | (let ((chinese-new-year | |
424 | (calendar-gregorian-from-absolute | |
465323b6 | 425 | (cadr (assoc 1 (chinese-year y)))))) |
0808d911 | 426 | (if (calendar-date-is-visible-p chinese-new-year) |
b4cb70c4 ER |
427 | (list |
428 | (list chinese-new-year | |
429 | (format "Chinese New Year (%s)" | |
ba2a1fb0 | 430 | (calendar-chinese-sexagesimal-name (+ y 57)))))))))) |
0808d911 | 431 | |
1d0c7fdf | 432 | ;;;###cal-autoload |
0808d911 ER |
433 | (defun calendar-chinese-date-string (&optional date) |
434 | "String of Chinese date of Gregorian DATE. | |
435 | Defaults to today's date if DATE is not given." | |
436 | (let* ((a-date (calendar-absolute-from-gregorian | |
437 | (or date (calendar-current-date)))) | |
438 | (c-date (calendar-chinese-from-absolute a-date)) | |
439 | (cycle (car c-date)) | |
465323b6 GM |
440 | (year (cadr c-date)) |
441 | (month (nth 2 c-date)) | |
442 | (day (nth 3 c-date)) | |
0808d911 ER |
443 | (this-month (calendar-absolute-from-chinese |
444 | (list cycle year month 1))) | |
445 | (next-month (calendar-absolute-from-chinese | |
67d80173 ER |
446 | (list (if (= year 60) (1+ cycle) cycle) |
447 | (if (= (floor month) 12) (1+ year) year) | |
c97663f6 GM |
448 | ;; Remainder of (1+(floor month))/12, with |
449 | ;; 12 instead of 0. | |
450 | (1+ (mod (floor month) 12)) | |
67d80173 | 451 | 1))) |
0031509c | 452 | (m-cycle (% (+ (* year 5) (floor month)) 60))) |
b4cb70c4 | 453 | (format "Cycle %s, year %s (%s), %smonth %s%s, day %s (%s)" |
0808d911 | 454 | cycle |
ba2a1fb0 | 455 | year (calendar-chinese-sexagesimal-name year) |
0808d911 ER |
456 | (if (not (integerp month)) |
457 | "second " | |
458 | (if (< 30 (- next-month this-month)) | |
459 | "first " | |
460 | "")) | |
0031509c | 461 | (floor month) |
b4cb70c4 | 462 | (if (integerp month) |
ba2a1fb0 | 463 | (format " (%s)" (calendar-chinese-sexagesimal-name |
cc6e0522 | 464 | (+ (* 12 year) month 50))) |
b4cb70c4 | 465 | "") |
ba2a1fb0 | 466 | day (calendar-chinese-sexagesimal-name (+ a-date 15))))) |
b4cb70c4 | 467 | |
1d0c7fdf | 468 | ;;;###cal-autoload |
0808d911 ER |
469 | (defun calendar-print-chinese-date () |
470 | "Show the Chinese date equivalents of date." | |
471 | (interactive) | |
472 | (message "Computing Chinese date...") | |
473 | (message "Chinese date: %s" | |
474 | (calendar-chinese-date-string (calendar-cursor-to-date t)))) | |
475 | ||
465323b6 GM |
476 | (defun make-chinese-month-assoc-list (l) |
477 | "Make list of months L into an assoc list." | |
478 | (and l (car l) | |
479 | (if (and (cdr l) (cadr l)) | |
480 | (if (= (car l) (floor (cadr l))) | |
481 | (append | |
482 | (list (cons (format "%s (first)" (car l)) (car l)) | |
483 | (cons (format "%s (second)" (car l)) (cadr l))) | |
484 | (make-chinese-month-assoc-list (cddr l))) | |
485 | (append | |
486 | (list (cons (int-to-string (car l)) (car l))) | |
487 | (make-chinese-month-assoc-list (cdr l)))) | |
488 | (list (cons (int-to-string (car l)) (car l)))))) | |
489 | ||
490 | (defun chinese-months (c y) | |
491 | "A list of the months in cycle C, year Y of the Chinese calendar." | |
492 | (memq 1 (append | |
493 | (mapcar (lambda (x) | |
494 | (car x)) | |
495 | (chinese-year (extract-calendar-year | |
496 | (calendar-gregorian-from-absolute | |
497 | (calendar-absolute-from-chinese | |
498 | (list c y 1 1)))))) | |
499 | (mapcar (lambda (x) | |
500 | (if (> (car x) 11) (car x))) | |
501 | (chinese-year (extract-calendar-year | |
502 | (calendar-gregorian-from-absolute | |
503 | (calendar-absolute-from-chinese | |
504 | (list (if (= y 60) (1+ c) c) | |
505 | (if (= y 60) 1 y) | |
506 | 1 1))))))))) | |
507 | ||
1d0c7fdf | 508 | ;;;###cal-autoload |
0808d911 ER |
509 | (defun calendar-goto-chinese-date (date &optional noecho) |
510 | "Move cursor to Chinese date DATE. | |
465323b6 | 511 | Echo Chinese date unless NOECHO is non-nil." |
0808d911 ER |
512 | (interactive |
513 | (let* ((c (calendar-chinese-from-absolute | |
465323b6 | 514 | (calendar-absolute-from-gregorian (calendar-current-date)))) |
0808d911 | 515 | (cycle (calendar-read |
0031509c | 516 | "Chinese calendar cycle number (>44): " |
bfcb5172 | 517 | (lambda (x) (> x 44)) |
0808d911 ER |
518 | (int-to-string (car c)))) |
519 | (year (calendar-read | |
0031509c | 520 | "Year in Chinese cycle (1..60): " |
bfcb5172 | 521 | (lambda (x) (and (<= 1 x) (<= x 60))) |
465323b6 | 522 | (int-to-string (cadr c)))) |
0031509c ER |
523 | (month-list (make-chinese-month-assoc-list |
524 | (chinese-months cycle year))) | |
525 | (month (cdr (assoc | |
526 | (completing-read "Chinese calendar month: " | |
527 | month-list nil t) | |
528 | month-list))) | |
529 | (last (if (= month | |
465323b6 GM |
530 | (nth 2 |
531 | (calendar-chinese-from-absolute | |
532 | (+ 29 | |
533 | (calendar-absolute-from-chinese | |
534 | (list cycle year month 1)))))) | |
0031509c ER |
535 | 30 |
536 | 29)) | |
537 | (day (calendar-read | |
538 | (format "Chinese calendar day (1-%d): " last) | |
bfcb5172 | 539 | (lambda (x) (and (<= 1 x) (<= x last)))))) |
0808d911 ER |
540 | (list (list cycle year month day)))) |
541 | (calendar-goto-date (calendar-gregorian-from-absolute | |
542 | (calendar-absolute-from-chinese date))) | |
543 | (or noecho (calendar-print-chinese-date))) | |
544 | ||
d7af270b GM |
545 | (defvar date) |
546 | ||
547 | ;; To be called from list-sexp-diary-entries, where DATE is bound. | |
1d0c7fdf | 548 | ;;;###diary-autoload |
0808d911 ER |
549 | (defun diary-chinese-date () |
550 | "Chinese calendar equivalent of date diary entry." | |
551 | (format "Chinese date: %s" (calendar-chinese-date-string date))) | |
552 | ||
c86b6d44 | 553 | (provide 'cal-china) |
0808d911 | 554 | |
bfcb5172 | 555 | ;; arch-tag: 7e5b7e0d-676c-47e3-8696-93e7ea0ab644 |
c86b6d44 | 556 | ;;; cal-china.el ends here |