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c86b6d44 | 1 | ;;; cal-china.el --- calendar functions for the Chinese calendar. |
0808d911 | 2 | |
a96a5fca | 3 | ;; Copyright (C) 1995, 1997 Free Software Foundation, Inc. |
0808d911 ER |
4 | |
5 | ;; Author: Edward M. Reingold <reingold@cs.uiuc.edu> | |
6 | ;; Keywords: calendar | |
7 | ;; Human-Keywords: Chinese calendar, calendar, holidays, diary | |
8 | ||
9 | ;; This file is part of GNU Emacs. | |
10 | ||
11 | ;; GNU Emacs is free software; you can redistribute it and/or modify | |
12 | ;; it under the terms of the GNU General Public License as published by | |
13 | ;; the Free Software Foundation; either version 2, or (at your option) | |
14 | ;; any later version. | |
15 | ||
16 | ;; GNU Emacs is distributed in the hope that it will be useful, | |
17 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
18 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
19 | ;; GNU General Public License for more details. | |
20 | ||
21 | ;; You should have received a copy of the GNU General Public License | |
b578f267 EN |
22 | ;; along with GNU Emacs; see the file COPYING. If not, write to the |
23 | ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
24 | ;; Boston, MA 02111-1307, USA. | |
0808d911 ER |
25 | |
26 | ;;; Commentary: | |
27 | ||
28 | ;; This collection of functions implements the features of calendar.el, | |
0031509c ER |
29 | ;; diary.el, and holidays.el that deal with the Chinese calendar. The rules |
30 | ;; used for the Chinese calendar are those of Baolin Liu (see L. E. Doggett's | |
31 | ;; article "Calendars" in the Explanatory Supplement to the Astronomical | |
32 | ;; Almanac, second edition, 1992) for the calendar as revised at the beginning | |
67d80173 ER |
33 | ;; of the Qing dynasty in 1644. The nature of the astronomical calculations |
34 | ;; is such that precise calculations cannot be made without great expense in | |
35 | ;; time, so that the calendars produced may not agree perfectly with published | |
36 | ;; tables--but no two pairs of published tables agree perfectly either! Liu's | |
37 | ;; rules produce a calendar for 2033 which is not accepted by all authorities. | |
38 | ;; The date of Chinese New Year is correct from 1644-2051. | |
0031509c | 39 | |
a96a5fca PE |
40 | ;; Technical details of all the calendrical calculations can be found in |
41 | ;; ``Calendrical Calculations'' by Nachum Dershowitz and Edward M. Reingold, | |
42 | ;; Cambridge University Press (1997). | |
43 | ||
0031509c | 44 | ;; Comments, corrections, and improvements should be sent to |
0808d911 ER |
45 | ;; Edward M. Reingold Department of Computer Science |
46 | ;; (217) 333-6733 University of Illinois at Urbana-Champaign | |
47 | ;; reingold@cs.uiuc.edu 1304 West Springfield Avenue | |
48 | ;; Urbana, Illinois 61801 | |
49 | ||
50 | ;;; Code: | |
51 | ||
52 | (require 'lunar) | |
53 | ||
0808d911 ER |
54 | (defvar chinese-calendar-celestial-stem |
55 | ["Jia" "Yi" "Bing" "Ding" "Wu" "Ji" "Geng" "Xin" "Ren" "Gui"]) | |
56 | ||
00e3e480 ER |
57 | (defvar chinese-calendar-terrestrial-branch |
58 | ["Zi" "Chou" "Yin" "Mao" "Chen" "Si" "Wu" "Wei" "Shen" "You" "Xu" "Hai"]) | |
59 | ||
8db540c5 | 60 | (defcustom chinese-calendar-time-zone |
0808d911 ER |
61 | '(if (< year 1928) |
62 | (+ 465 (/ 40.0 60.0)) | |
63 | 480) | |
64 | "*Number of minutes difference between local standard time for Chinese | |
65 | calendar and Coordinated Universal (Greenwich) Time. Default is for Beijing. | |
66 | This is an expression in `year' since it changed at 1928-01-01 00:00:00 from | |
8db540c5 | 67 | UT+7:45:40 to UT+8." |
9e935048 | 68 | :type 'sexp |
8db540c5 | 69 | :group 'chinese-calendar) |
0808d911 | 70 | |
8db540c5 RS |
71 | (defcustom chinese-calendar-location-name "Beijing" |
72 | "*Name of location used for calculation of Chinese calendar." | |
73 | :type 'string | |
74 | :group 'chinese-calendar) | |
0808d911 | 75 | |
8db540c5 | 76 | (defcustom chinese-calendar-daylight-time-offset 0 |
00e3e480 ER |
77 | ; The correct value is as follows, but the Chinese calendrical |
78 | ; authorities do NOT use DST in determining astronomical events: | |
79 | ; 60 | |
0808d911 | 80 | "*Number of minutes difference between daylight savings and standard time |
8db540c5 RS |
81 | for Chinese calendar. Default is for no daylight savings time." |
82 | :type 'integer | |
83 | :group 'chinese-calendar) | |
0808d911 | 84 | |
8db540c5 | 85 | (defcustom chinese-calendar-standard-time-zone-name |
0808d911 ER |
86 | '(if (< year 1928) |
87 | "PMT" | |
88 | "CST") | |
9e935048 RS |
89 | "*Abbreviated name of standard time zone used for Chinese calendar. |
90 | This is an expression depending on `year' because it changed | |
91 | at 1928-01-01 00:00:00 from `PMT' to `CST'." | |
92 | :type 'sexp | |
8db540c5 | 93 | :group 'chinese-calendar) |
0808d911 | 94 | |
8db540c5 RS |
95 | (defcustom chinese-calendar-daylight-time-zone-name "CDT" |
96 | "*Abbreviated name of daylight-savings time zone used for Chinese calendar." | |
97 | :type 'string | |
98 | :group 'chinese-calendar) | |
0808d911 | 99 | |
8db540c5 | 100 | (defcustom chinese-calendar-daylight-savings-starts nil |
00e3e480 ER |
101 | ; The correct value is as follows, but the Chinese calendrical |
102 | ; authorities do NOT use DST in determining astronomical events: | |
103 | ; '(cond ((< 1986 year) (calendar-nth-named-day 1 0 4 year 10)) | |
104 | ; ((= 1986 year) '(5 4 1986)) | |
105 | ; (t nil)) | |
0808d911 | 106 | "*Sexp giving the date on which daylight savings time starts for Chinese |
00e3e480 | 107 | calendar. Default is for no daylight savings time. See documentation of |
8db540c5 RS |
108 | `calendar-daylight-savings-starts'." |
109 | :type 'sexp | |
110 | :group 'chinese-calendar) | |
0808d911 | 111 | |
8db540c5 | 112 | (defcustom chinese-calendar-daylight-savings-ends nil |
00e3e480 ER |
113 | ; The correct value is as follows, but the Chinese calendrical |
114 | ; authorities do NOT use DST in determining astronomical events: | |
115 | ; '(if (<= 1986 year) (calendar-nth-named-day 1 0 9 year 11)) | |
0808d911 | 116 | "*Sexp giving the date on which daylight savings time ends for Chinese |
00e3e480 | 117 | calendar. Default is for no daylight savings time. See documentation of |
8db540c5 RS |
118 | `calendar-daylight-savings-ends'." |
119 | :type 'sexp | |
120 | :group 'chinese-calendar) | |
0808d911 | 121 | |
8db540c5 | 122 | (defcustom chinese-calendar-daylight-savings-starts-time 0 |
0808d911 | 123 | "*Number of minutes after midnight that daylight savings time starts for |
8db540c5 RS |
124 | Chinese calendar. Default is for no daylight savings time." |
125 | :type 'integer | |
126 | :group 'chinese-calendar) | |
0808d911 | 127 | |
8db540c5 | 128 | (defcustom chinese-calendar-daylight-savings-ends-time 0 |
0808d911 | 129 | "*Number of minutes after midnight that daylight savings time ends for |
8db540c5 RS |
130 | Chinese calendar. Default is for no daylight savings time." |
131 | :type 'integer | |
132 | :group 'chinese-calendar) | |
0808d911 ER |
133 | |
134 | (defun chinese-zodiac-sign-on-or-after (d) | |
135 | "Absolute date of first new Zodiac sign on or after absolute date d. | |
136 | The Zodiac signs begin when the sun's longitude is a multiple of 30 degrees." | |
137 | (let* ((year (extract-calendar-year | |
0031509c | 138 | (calendar-gregorian-from-absolute d))) |
0808d911 ER |
139 | (calendar-time-zone (eval chinese-calendar-time-zone)) |
140 | (calendar-daylight-time-offset | |
141 | chinese-calendar-daylight-time-offset) | |
142 | (calendar-standard-time-zone-name | |
143 | chinese-calendar-standard-time-zone-name) | |
144 | (calendar-daylight-time-zone-name | |
145 | chinese-calendar-daylight-time-zone-name) | |
146 | (calendar-calendar-daylight-savings-starts | |
147 | chinese-calendar-daylight-savings-starts) | |
148 | (calendar-daylight-savings-ends | |
149 | chinese-calendar-daylight-savings-ends) | |
150 | (calendar-daylight-savings-starts-time | |
151 | chinese-calendar-daylight-savings-starts-time) | |
152 | (calendar-daylight-savings-ends-time | |
153 | chinese-calendar-daylight-savings-ends-time)) | |
154 | (floor | |
155 | (calendar-absolute-from-astro | |
156 | (solar-date-next-longitude | |
157 | (calendar-astro-from-absolute d) | |
158 | 30))))) | |
159 | ||
160 | (defun chinese-new-moon-on-or-after (d) | |
161 | "Absolute date of first new moon on or after absolute date d." | |
162 | (let* ((year (extract-calendar-year | |
163 | (calendar-gregorian-from-absolute d))) | |
164 | (calendar-time-zone (eval chinese-calendar-time-zone)) | |
165 | (calendar-daylight-time-offset | |
166 | chinese-calendar-daylight-time-offset) | |
167 | (calendar-standard-time-zone-name | |
168 | chinese-calendar-standard-time-zone-name) | |
169 | (calendar-daylight-time-zone-name | |
170 | chinese-calendar-daylight-time-zone-name) | |
171 | (calendar-calendar-daylight-savings-starts | |
172 | chinese-calendar-daylight-savings-starts) | |
173 | (calendar-daylight-savings-ends | |
174 | chinese-calendar-daylight-savings-ends) | |
175 | (calendar-daylight-savings-starts-time | |
176 | chinese-calendar-daylight-savings-starts-time) | |
177 | (calendar-daylight-savings-ends-time | |
178 | chinese-calendar-daylight-savings-ends-time)) | |
179 | (floor | |
180 | (calendar-absolute-from-astro | |
181 | (lunar-new-moon-on-or-after | |
182 | (calendar-astro-from-absolute d)))))) | |
183 | ||
0031509c | 184 | (defvar chinese-year-cache |
00e3e480 ER |
185 | '((1989 (12 726110) (1 726139) (2 726169) (3 726198) (4 726227) (5 726257) |
186 | (6 726286) (7 726316) (8 726345) (9 726375) (10 726404) (11 726434)) | |
187 | (1990 (12 726464) (1 726494) (2 726523) (3 726553) (4 726582) (5 726611) | |
188 | (5.5 726641) (6 726670) (7 726699) (8 726729) (9 726758) (10 726788) | |
189 | (11 726818)) | |
190 | (1991 (12 726848) (1 726878) (2 726907) (3 726937) (4 726966) (5 726995) | |
191 | (6 727025) (7 727054) (8 727083) (9 727113) (10 727142) (11 727172)) | |
192 | (1992 (12 727202) (1 727232) (2 727261) (3 727291) (4 727321) (5 727350) | |
193 | (6 727379) (7 727409) (8 727438) (9 727467) (10 727497) (11 727526)) | |
194 | (1993 (12 727556) (1 727586) (2 727615) (3 727645) (3.5 727675) (4 727704) | |
195 | (5 727734) (6 727763) (7 727793) (8 727822) (9 727851) (10 727881) | |
196 | (11 727910)) | |
197 | (1994 (12 727940) (1 727969) (2 727999) (3 728029) (4 728059) (5 728088) | |
198 | (6 728118) (7 728147) (8 728177) (9 728206) (10 728235) (11 728265)) | |
199 | (1995 (12 728294) (1 728324) (2 728353) (3 728383) (4 728413) (5 728442) | |
200 | (6 728472) (7 728501) (8 728531) (8.5 728561) (9 728590) (10 728619) | |
201 | (11 728649)) | |
202 | (1996 (12 728678) (1 728708) (2 728737) (3 728767) (4 728796) (5 728826) | |
203 | (6 728856) (7 728885) (8 728915) (9 728944) (10 728974) (11 729004)) | |
204 | (1997 (12 729033) (1 729062) (2 729092) (3 729121) (4 729151) (5 729180) | |
205 | (6 729210) (7 729239) (8 729269) (9 729299) (10 729328) (11 729358)) | |
206 | (1998 (12 729388) (1 729417) (2 729447) (3 729476) (4 729505) (5 729535) | |
207 | (5.5 729564) (6 729593) (7 729623) (8 729653) (9 729682) (10 729712) | |
208 | (11 729742)) | |
209 | (1999 (12 729771) (1 729801) (2 729831) (3 729860) (4 729889) (5 729919) | |
210 | (6 729948) (7 729977) (8 730007) (9 730036) (10 730066) (11 730096)) | |
211 | (2000 (12 730126) (1 730155) (2 730185) (3 730215) (4 730244) (5 730273) | |
212 | (6 730303) (7 730332) (8 730361) (9 730391) (10 730420) (11 730450))) | |
0031509c ER |
213 | "An assoc list of Chinese year structures as determined by `chinese-year'. |
214 | ||
215 | Values are computed as needed, but to save time, the initial value consists | |
216 | of the precomputed years 1989-2000. The code works just as well with this | |
217 | set to nil initially (which is how the value for 1989-2000 was computed).") | |
218 | ||
219 | (defun chinese-year (y) | |
220 | "The structure of the Chinese year for Gregorian year Y. | |
00e3e480 | 221 | The result is a list of pairs (i d), where month i begins on absolute date d, |
0031509c ER |
222 | of the Chinese months from the Chinese month following the solstice in |
223 | Gregorian year Y-1 to the Chinese month of the solstice of Gregorian year Y. | |
224 | ||
225 | The list is cached for further use." | |
226 | (let ((list (cdr (assoc y chinese-year-cache)))) | |
227 | (if (not list) | |
228 | (progn | |
229 | (setq list (compute-chinese-year y)) | |
230 | (setq chinese-year-cache | |
00e3e480 | 231 | (append chinese-year-cache (list (cons y list)))))) |
0031509c ER |
232 | list)) |
233 | ||
67d80173 | 234 | (defun number-chinese-months (list start) |
0031509c | 235 | "Assign month numbers to the lunar months in LIST, starting with START. |
67d80173 ER |
236 | Numbers are assigned sequentially, START, START+1, ..., 11, with half |
237 | numbers used for leap months. | |
0031509c | 238 | |
67d80173 | 239 | First month of list will never be a leap month, nor will the last." |
0031509c | 240 | (if list |
67d80173 ER |
241 | (if (zerop (- 12 start (length list))) |
242 | ;; List is too short for a leap month | |
00e3e480 | 243 | (cons (list start (car list)) |
67d80173 | 244 | (number-chinese-months (cdr list) (1+ start))) |
0031509c | 245 | (cons |
67d80173 | 246 | ;; First month |
00e3e480 | 247 | (list start (car list)) |
67d80173 | 248 | ;; Remaining months |
0031509c | 249 | (if (and (cdr (cdr list));; at least two more months... |
0031509c ER |
250 | (<= (car (cdr (cdr list))) |
251 | (chinese-zodiac-sign-on-or-after (car (cdr list))))) | |
67d80173 | 252 | ;; Next month is a leap month |
00e3e480 | 253 | (cons (list (+ start 0.5) (car (cdr list))) |
67d80173 ER |
254 | (number-chinese-months (cdr (cdr list)) (1+ start))) |
255 | ;; Next month is not a leap month | |
0031509c ER |
256 | (number-chinese-months (cdr list) (1+ start))))))) |
257 | ||
258 | (defun chinese-month-list (start end) | |
259 | "List of starting dates of Chinese months from START to END." | |
260 | (if (<= start end) | |
261 | (let ((new-moon (chinese-new-moon-on-or-after start))) | |
262 | (if (<= new-moon end) | |
00e3e480 ER |
263 | (cons new-moon |
264 | (chinese-month-list (1+ new-moon) end)))))) | |
0031509c | 265 | |
0031509c ER |
266 | (defun compute-chinese-year (y) |
267 | "Compute the structure of the Chinese year for Gregorian year Y. | |
00e3e480 | 268 | The result is a list of pairs (i d), where month i begins on absolute date d, |
0031509c ER |
269 | of the Chinese months from the Chinese month following the solstice in |
270 | Gregorian year Y-1 to the Chinese month of the solstice of Gregorian year Y." | |
271 | (let* ((next-solstice (chinese-zodiac-sign-on-or-after | |
272 | (calendar-absolute-from-gregorian | |
273 | (list 12 15 y)))) | |
274 | (list (chinese-month-list (1+ (chinese-zodiac-sign-on-or-after | |
275 | (calendar-absolute-from-gregorian | |
276 | (list 12 15 (1- y))))) | |
67d80173 ER |
277 | next-solstice)) |
278 | (next-sign (chinese-zodiac-sign-on-or-after (car list)))) | |
0031509c ER |
279 | (if (= (length list) 12) |
280 | ;; No room for a leap month, just number them 12, 1, 2, ..., 11 | |
00e3e480 | 281 | (cons (list 12 (car list)) |
67d80173 ER |
282 | (number-chinese-months (cdr list) 1)) |
283 | ;; Now we can assign numbers to the list for y | |
284 | ;; The first month or two are special | |
285 | (if (or (> (car list) next-sign) (>= next-sign (car (cdr list)))) | |
286 | ;; First month on list is a leap month, second is not | |
00e3e480 ER |
287 | (append (list (list 11.5 (car list)) |
288 | (list 12 (car (cdr list)))) | |
67d80173 ER |
289 | (number-chinese-months (cdr (cdr list)) 1)) |
290 | ;; First month on list is not a leap month | |
00e3e480 | 291 | (append (list (list 12 (car list))) |
67d80173 ER |
292 | (if (>= (chinese-zodiac-sign-on-or-after (car (cdr list))) |
293 | (car (cdr (cdr list)))) | |
294 | ;; Second month on list is a leap month | |
00e3e480 | 295 | (cons (list 12.5 (car (cdr list))) |
67d80173 ER |
296 | (number-chinese-months (cdr (cdr list)) 1)) |
297 | ;; Second month on list is not a leap month | |
298 | (number-chinese-months (cdr list) 1))))))) | |
0031509c | 299 | |
0808d911 ER |
300 | (defun calendar-absolute-from-chinese (date) |
301 | "The number of days elapsed between the Gregorian date 12/31/1 BC and DATE. | |
302 | The Gregorian date Sunday, December 31, 1 BC is imaginary." | |
303 | (let* ((cycle (car date)) | |
304 | (year (car (cdr date))) | |
305 | (month (car (cdr (cdr date)))) | |
306 | (day (car (cdr (cdr (cdr date))))) | |
307 | (g-year (+ (* (1- cycle) 60);; years in prior cycles | |
0031509c ER |
308 | (1- year) ;; prior years this cycle |
309 | -2636))) ;; years before absolute date 0 | |
310 | (+ (1- day);; prior days this month | |
00e3e480 ER |
311 | (car |
312 | (cdr ;; absolute date of start of this month | |
313 | (assoc month (append (memq (assoc 1 (chinese-year g-year)) | |
314 | (chinese-year g-year)) | |
315 | (chinese-year (1+ g-year))))))))) | |
0808d911 ER |
316 | |
317 | (defun calendar-chinese-from-absolute (date) | |
318 | "Compute Chinese date (cycle year month day) corresponding to absolute DATE. | |
319 | The absolute date is the number of days elapsed since the (imaginary) | |
320 | Gregorian date Sunday, December 31, 1 BC." | |
0031509c ER |
321 | (let* ((g-year (extract-calendar-year |
322 | (calendar-gregorian-from-absolute date))) | |
00e3e480 | 323 | (c-year (+ g-year 2695)) |
0031509c ER |
324 | (list (append (chinese-year (1- g-year)) |
325 | (chinese-year g-year) | |
326 | (chinese-year (1+ g-year))))) | |
00e3e480 ER |
327 | (while (<= (car (cdr (car (cdr list)))) date) |
328 | ;; the first month on the list is in Chinese year c-year | |
329 | ;; date is on or after start of second month on list... | |
0031509c | 330 | (if (= 1 (car (car (cdr list)))) |
00e3e480 ER |
331 | ;; second month on list is a new Chinese year |
332 | (setq c-year (1+ c-year))) | |
333 | ;; ...so first month on list is of no interest | |
0031509c | 334 | (setq list (cdr list))) |
00e3e480 ER |
335 | (list (/ (1- c-year) 60) |
336 | (calendar-mod c-year 60) | |
0031509c | 337 | (car (car list)) |
00e3e480 | 338 | (1+ (- date (car (cdr (car list)))))))) |
0808d911 ER |
339 | |
340 | (defun holiday-chinese-new-year () | |
341 | "Date of Chinese New Year." | |
342 | (let ((m displayed-month) | |
343 | (y displayed-year)) | |
344 | (increment-calendar-month m y 1) | |
345 | (if (< m 5) | |
346 | (let ((chinese-new-year | |
347 | (calendar-gregorian-from-absolute | |
00e3e480 | 348 | (car (cdr (assoc 1 (chinese-year y))))))) |
0808d911 | 349 | (if (calendar-date-is-visible-p chinese-new-year) |
b4cb70c4 ER |
350 | (list |
351 | (list chinese-new-year | |
352 | (format "Chinese New Year (%s)" | |
ba2a1fb0 | 353 | (calendar-chinese-sexagesimal-name (+ y 57)))))))))) |
0808d911 ER |
354 | |
355 | (defun calendar-chinese-date-string (&optional date) | |
356 | "String of Chinese date of Gregorian DATE. | |
357 | Defaults to today's date if DATE is not given." | |
358 | (let* ((a-date (calendar-absolute-from-gregorian | |
359 | (or date (calendar-current-date)))) | |
360 | (c-date (calendar-chinese-from-absolute a-date)) | |
361 | (cycle (car c-date)) | |
362 | (year (car (cdr c-date))) | |
363 | (month (car (cdr (cdr c-date)))) | |
364 | (day (car (cdr (cdr (cdr c-date))))) | |
365 | (this-month (calendar-absolute-from-chinese | |
366 | (list cycle year month 1))) | |
367 | (next-month (calendar-absolute-from-chinese | |
67d80173 ER |
368 | (list (if (= year 60) (1+ cycle) cycle) |
369 | (if (= (floor month) 12) (1+ year) year) | |
370 | (calendar-mod (1+ (floor month)) 12) | |
371 | 1))) | |
0031509c | 372 | (m-cycle (% (+ (* year 5) (floor month)) 60))) |
b4cb70c4 | 373 | (format "Cycle %s, year %s (%s), %smonth %s%s, day %s (%s)" |
0808d911 | 374 | cycle |
ba2a1fb0 | 375 | year (calendar-chinese-sexagesimal-name year) |
0808d911 ER |
376 | (if (not (integerp month)) |
377 | "second " | |
378 | (if (< 30 (- next-month this-month)) | |
379 | "first " | |
380 | "")) | |
0031509c | 381 | (floor month) |
b4cb70c4 | 382 | (if (integerp month) |
ba2a1fb0 | 383 | (format " (%s)" (calendar-chinese-sexagesimal-name |
cc6e0522 | 384 | (+ (* 12 year) month 50))) |
b4cb70c4 | 385 | "") |
ba2a1fb0 | 386 | day (calendar-chinese-sexagesimal-name (+ a-date 15))))) |
b4cb70c4 | 387 | |
ba2a1fb0 PE |
388 | (defun calendar-chinese-sexagesimal-name (n) |
389 | "The N-th name of the Chinese sexagesimal cycle. | |
b4cb70c4 ER |
390 | N congruent to 1 gives the first name, N congruent to 2 gives the second name, |
391 | ..., N congruent to 60 gives the sixtieth name." | |
392 | (format "%s-%s" | |
393 | (aref chinese-calendar-celestial-stem (% (1- n) 10)) | |
394 | (aref chinese-calendar-terrestrial-branch (% (1- n) 12)))) | |
0808d911 ER |
395 | |
396 | (defun calendar-print-chinese-date () | |
397 | "Show the Chinese date equivalents of date." | |
398 | (interactive) | |
399 | (message "Computing Chinese date...") | |
400 | (message "Chinese date: %s" | |
401 | (calendar-chinese-date-string (calendar-cursor-to-date t)))) | |
402 | ||
403 | (defun calendar-goto-chinese-date (date &optional noecho) | |
404 | "Move cursor to Chinese date DATE. | |
405 | Echo Chinese date unless NOECHO is t." | |
406 | (interactive | |
407 | (let* ((c (calendar-chinese-from-absolute | |
408 | (calendar-absolute-from-gregorian | |
409 | (calendar-current-date)))) | |
410 | (cycle (calendar-read | |
0031509c | 411 | "Chinese calendar cycle number (>44): " |
0808d911 ER |
412 | '(lambda (x) (> x 44)) |
413 | (int-to-string (car c)))) | |
414 | (year (calendar-read | |
0031509c | 415 | "Year in Chinese cycle (1..60): " |
0808d911 ER |
416 | '(lambda (x) (and (<= 1 x) (<= x 60))) |
417 | (int-to-string (car (cdr c))))) | |
0031509c ER |
418 | (month-list (make-chinese-month-assoc-list |
419 | (chinese-months cycle year))) | |
420 | (month (cdr (assoc | |
421 | (completing-read "Chinese calendar month: " | |
422 | month-list nil t) | |
423 | month-list))) | |
424 | (last (if (= month | |
425 | (car (cdr (cdr | |
426 | (calendar-chinese-from-absolute | |
427 | (+ 29 | |
428 | (calendar-absolute-from-chinese | |
429 | (list cycle year month 1)))))))) | |
430 | 30 | |
431 | 29)) | |
432 | (day (calendar-read | |
433 | (format "Chinese calendar day (1-%d): " last) | |
434 | '(lambda (x) (and (<= 1 x) (<= x last)))))) | |
0808d911 ER |
435 | (list (list cycle year month day)))) |
436 | (calendar-goto-date (calendar-gregorian-from-absolute | |
437 | (calendar-absolute-from-chinese date))) | |
438 | (or noecho (calendar-print-chinese-date))) | |
439 | ||
0031509c ER |
440 | (defun chinese-months (c y) |
441 | "A list of the months in cycle C, year Y of the Chinese calendar." | |
442 | (let* ((l (memq 1 (append | |
443 | (mapcar '(lambda (x) | |
444 | (car x)) | |
445 | (chinese-year (extract-calendar-year | |
446 | (calendar-gregorian-from-absolute | |
447 | (calendar-absolute-from-chinese | |
448 | (list c y 1 1)))))) | |
449 | (mapcar '(lambda (x) | |
450 | (if (> (car x) 11) (car x))) | |
451 | (chinese-year (extract-calendar-year | |
452 | (calendar-gregorian-from-absolute | |
453 | (calendar-absolute-from-chinese | |
454 | (list (if (= y 60) (1+ c) c) | |
455 | (if (= y 60) 1 y) | |
456 | 1 1)))))))))) | |
457 | l)) | |
458 | ||
459 | (defun make-chinese-month-assoc-list (l) | |
460 | "Make list of months L into an assoc list." | |
461 | (if (and l (car l)) | |
462 | (if (and (cdr l) (car (cdr l))) | |
463 | (if (= (car l) (floor (car (cdr l)))) | |
464 | (append | |
465 | (list (cons (format "%s (first)" (car l)) (car l)) | |
466 | (cons (format "%s (second)" (car l)) (car (cdr l)))) | |
467 | (make-chinese-month-assoc-list (cdr (cdr l)))) | |
468 | (append | |
469 | (list (cons (int-to-string (car l)) (car l))) | |
470 | (make-chinese-month-assoc-list (cdr l)))) | |
471 | (list (cons (int-to-string (car l)) (car l)))))) | |
472 | ||
0808d911 ER |
473 | (defun diary-chinese-date () |
474 | "Chinese calendar equivalent of date diary entry." | |
475 | (format "Chinese date: %s" (calendar-chinese-date-string date))) | |
476 | ||
c86b6d44 | 477 | (provide 'cal-china) |
0808d911 | 478 | |
c86b6d44 | 479 | ;;; cal-china.el ends here |