Mercurial > hg > xemacs-beta

comparison lisp/calendar/holidays.el @ 0:376386a54a3c r19-14

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Import from CVS: tag r19-14
author cvs
date Mon, 13 Aug 2007 08:45:50 +0200
parents
children 0293115a14e9
comparison
equal deleted inserted replaced
-1:000000000000 0:376386a54a3c
1 ;;; holidays.el --- holiday functions for the calendar package
2
3 ;;; Copyright (C) 1989, 1990, 1992, 1993, 1994 Free Software Foundation, Inc.
4
5 ;; Author: Edward M. Reingold <reingold@cs.uiuc.edu>
6 ;; Keywords: holidays, calendar
7
8 ;; This file is part of XEmacs.
9
10 ;; XEmacs is free software; you can redistribute it and/or modify it
11 ;; under the terms of the GNU General Public License as published by
12 ;; the Free Software Foundation; either version 2, or (at your option)
13 ;; any later version.
14
15 ;; XEmacs is distributed in the hope that it will be useful, but
16 ;; WITHOUT ANY WARRANTY; without even the implied warranty of
17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 ;; General Public License for more details.
19
20 ;; You should have received a copy of the GNU General Public License
21 ;; along with XEmacs; see the file COPYING. If not, write to the Free
22 ;; Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
23
24 ;;; Commentary:
25
26 ;; This collection of functions implements the holiday features as described
27 ;; in calendar.el.
28
29 ;; Comments, corrections, and improvements should be sent to
30 ;; Edward M. Reingold Department of Computer Science
31 ;; (217) 333-6733 University of Illinois at Urbana-Champaign
32 ;; reingold@cs.uiuc.edu 1304 West Springfield Avenue
33 ;; Urbana, Illinois 61801
34
35 ;; Technical details of all the calendrical calculations can be found in
36 ;; ``Calendrical Calculations'' by Nachum Dershowitz and Edward M. Reingold,
37 ;; Software--Practice and Experience, Volume 20, Number 9 (September, 1990),
38 ;; pages 899-928. ``Calendrical Calculations, Part II: Three Historical
39 ;; Calendars'' by E. M. Reingold, N. Dershowitz, and S. M. Clamen,
40 ;; Software--Practice and Experience, Volume 23, Number 4 (April, 1993),
41 ;; pages 383-404.
42
43 ;; Hard copies of these two papers can be obtained by sending email to
44 ;; reingold@cs.uiuc.edu with the SUBJECT "send-paper-cal" (no quotes) and
45 ;; the message BODY containing your mailing address (snail).
46
47 ;;; Code:
48
49 (require 'calendar)
50
51 (autoload 'solar-equinoxes-solstices "solar"
52 "Date and time of equinoxes and solstices, if visible in the calendar window.
53 Requires floating point."
54 t)
55
56 ;;;###autoload
57 (defun holidays (&optional arg)
58 "Display the holidays for last month, this month, and next month.
59 If called with an optional prefix argument, prompts for month and year.
60
61 This function is suitable for execution in a .emacs file."
62 (interactive "P")
63 (save-excursion
64 (let* ((completion-ignore-case t)
65 (date (if arg
66 (calendar-read-date t)
67 (calendar-current-date)))
68 (displayed-month (extract-calendar-month date))
69 (displayed-year (extract-calendar-year date)))
70 (list-calendar-holidays))))
71
72 (defun check-calendar-holidays (date)
73 "Check the list of holidays for any that occur on DATE.
74 The value returned is a list of strings of relevant holiday descriptions.
75 The holidays are those in the list calendar-holidays."
76 (let* ((displayed-month (extract-calendar-month date))
77 (displayed-year (extract-calendar-year date))
78 (h (calendar-holiday-list))
79 (holiday-list))
80 (while h
81 (if (calendar-date-equal date (car (car h)))
82 (setq holiday-list (append holiday-list (cdr (car h)))))
83 (setq h (cdr h)))
84 holiday-list))
85
86 (defun calendar-cursor-holidays ()
87 "Find holidays for the date specified by the cursor in the calendar window."
88 (interactive)
89 (message "Checking holidays...")
90 (let* ((date (calendar-cursor-to-date t))
91 (date-string (calendar-date-string date))
92 (holiday-list (check-calendar-holidays date))
93 (holiday-string (mapconcat 'identity holiday-list "; "))
94 (msg (format "%s: %s" date-string holiday-string)))
95 (if (not holiday-list)
96 (message "No holidays known for %s" date-string)
97 (if (<= (length msg) (frame-width))
98 (message msg)
99 (set-buffer (get-buffer-create holiday-buffer))
100 (setq buffer-read-only nil)
101 (calendar-set-mode-line date-string)
102 (erase-buffer)
103 (insert (mapconcat 'identity holiday-list "\n"))
104 (goto-char (point-min))
105 (set-buffer-modified-p nil)
106 (setq buffer-read-only t)
107 (display-buffer holiday-buffer)
108 (message "Checking holidays...done")))))
109
110 (defun mark-calendar-holidays ()
111 "Mark notable days in the calendar window."
112 (interactive)
113 (setq mark-holidays-in-calendar t)
114 (message "Marking holidays...")
115 (let ((holiday-list (calendar-holiday-list)))
116 (while holiday-list
117 (mark-visible-calendar-date
118 (car (car holiday-list)) calendar-holiday-marker)
119 (setq holiday-list (cdr holiday-list))))
120 (message "Marking holidays...done"))
121
122 (defun list-calendar-holidays ()
123 "Create a buffer containing the holidays for the current calendar window.
124 The holidays are those in the list calendar-notable-days. Returns t if any
125 holidays are found, nil if not."
126 (interactive)
127 (message "Looking up holidays...")
128 (let ((holiday-list (calendar-holiday-list))
129 (m1 displayed-month)
130 (y1 displayed-year)
131 (m2 displayed-month)
132 (y2 displayed-year))
133 (if (not holiday-list)
134 (progn
135 (message "Looking up holidays...none found")
136 nil)
137 (set-buffer (get-buffer-create holiday-buffer))
138 (setq buffer-read-only nil)
139 (increment-calendar-month m1 y1 -1)
140 (increment-calendar-month m2 y2 1)
141 (calendar-set-mode-line
142 (if (= y1 y2)
143 (format "Notable Dates from %s to %s, %d%%-"
144 (calendar-month-name m1) (calendar-month-name m2) y2)
145 (format "Notable Dates from %s, %d to %s, %d%%-"
146 (calendar-month-name m1) y1 (calendar-month-name m2) y2)))
147 (erase-buffer)
148 (insert
149 (mapconcat
150 '(lambda (x) (concat (calendar-date-string (car x))
151 ": " (car (cdr x))))
152 holiday-list "\n"))
153 (goto-char (point-min))
154 (set-buffer-modified-p nil)
155 (setq buffer-read-only t)
156 (display-buffer holiday-buffer)
157 (message "Looking up holidays...done")
158 t)))
159
160 (defun calendar-holiday-list ()
161 "Form the list of holidays that occur on dates in the calendar window.
162 The holidays are those in the list calendar-holidays."
163 (let ((p calendar-holidays)
164 (holiday-list))
165 (while p
166 (let* ((holidays
167 (if calendar-debug-sexp
168 (let ((stack-trace-on-error t))
169 (eval (car p)))
170 (condition-case nil
171 (eval (car p))
172 (error (beep)
173 (message "Bad holiday list item: %s" (car p))
174 (sleep-for 2))))))
175 (if holidays
176 (setq holiday-list (append holidays holiday-list))))
177 (setq p (cdr p)))
178 (setq holiday-list (sort holiday-list 'calendar-date-compare))))
179
180 ;; Below are the functions that calculate the dates of holidays; these
181 ;; are eval'ed in the function calendar-holiday-list. If you
182 ;; write other such functions, be sure to imitate the style used below.
183 ;; Remember that each function must return a list of items of the form
184 ;; ((month day year) string) of VISIBLE dates in the calendar window.
185
186 (defun holiday-fixed (month day string)
187 "Holiday on MONTH, DAY (Gregorian) called STRING.
188 If MONTH, DAY is visible, the value returned is the list (((MONTH DAY year)
189 STRING)). Returns nil if it is not visible in the current calendar window."
190 (let ((m displayed-month)
191 (y displayed-year))
192 (increment-calendar-month m y (- 11 month))
193 (if (> m 9)
194 (list (list (list month day y) string)))))
195
196 (defun holiday-float (month dayname n string &optional day)
197 "Holiday on MONTH, DAYNAME (Nth occurrence, Gregorian) called STRING.
198 If the Nth DAYNAME in MONTH is visible, the value returned is the list
199 \(((MONTH DAY year) STRING)).
200
201 If N<0, count backward from the end of MONTH.
202
203 An optional parameter DAY means the Nth DAYNAME after/before MONTH DAY.
204
205 Returns nil if it is not visible in the current calendar window."
206 (let ((m displayed-month)
207 (y displayed-year))
208 (increment-calendar-month m y (- 11 month))
209 (if (> m 9)
210 (list (list (calendar-nth-named-day n dayname month y day) string)))))
211
212 (defun holiday-julian (month day string)
213 "Holiday on MONTH, DAY (Julian) called STRING.
214 If MONTH, DAY (Julian) is visible, the value returned is corresponding
215 Gregorian date in the form of the list (((month day year) STRING)). Returns
216 nil if it is not visible in the current calendar window."
217 (let ((m1 displayed-month)
218 (y1 displayed-year)
219 (m2 displayed-month)
220 (y2 displayed-year)
221 (year))
222 (increment-calendar-month m1 y1 -1)
223 (increment-calendar-month m2 y2 1)
224 (let* ((start-date (calendar-absolute-from-gregorian
225 (list m1 1 y1)))
226 (end-date (calendar-absolute-from-gregorian
227 (list m2 (calendar-last-day-of-month m2 y2) y2)))
228 (julian-start (calendar-julian-from-absolute start-date))
229 (julian-end (calendar-julian-from-absolute end-date))
230 (julian-y1 (extract-calendar-year julian-start))
231 (julian-y2 (extract-calendar-year julian-end)))
232 (setq year (if (< 10 month) julian-y1 julian-y2))
233 (let ((date (calendar-gregorian-from-absolute
234 (calendar-absolute-from-julian
235 (list month day year)))))
236 (if (calendar-date-is-visible-p date)
237 (list (list date string)))))))
238
239 (defun holiday-islamic (month day string)
240 "Holiday on MONTH, DAY (Islamic) called STRING.
241 If MONTH, DAY (Islamic) is visible, the value returned is corresponding
242 Gregorian date in the form of the list (((month day year) STRING)). Returns
243 nil if it is not visible in the current calendar window."
244 (let* ((islamic-date (calendar-islamic-from-absolute
245 (calendar-absolute-from-gregorian
246 (list displayed-month 15 displayed-year))))
247 (m (extract-calendar-month islamic-date))
248 (y (extract-calendar-year islamic-date))
249 (date))
250 (if (< m 1)
251 nil;; Islamic calendar doesn't apply.
252 (increment-calendar-month m y (- 10 month))
253 (if (> m 7);; Islamic date might be visible
254 (let ((date (calendar-gregorian-from-absolute
255 (calendar-absolute-from-islamic (list month day y)))))
256 (if (calendar-date-is-visible-p date)
257 (list (list date string))))))))
258
259 (defun holiday-hebrew (month day string)
260 "Holiday on MONTH, DAY (Hebrew) called STRING.
261 If MONTH, DAY (Hebrew) is visible, the value returned is corresponding
262 Gregorian date in the form of the list (((month day year) STRING)). Returns
263 nil if it is not visible in the current calendar window."
264 (if (memq displayed-month;; This test is only to speed things up a bit;
265 (list ;; it works fine without the test too.
266 (if (< 11 month) (- month 11) (+ month 1))
267 (if (< 10 month) (- month 10) (+ month 2))
268 (if (< 9 month) (- month 9) (+ month 3))
269 (if (< 8 month) (- month 8) (+ month 4))
270 (if (< 7 month) (- month 7) (+ month 5))))
271 (let ((m1 displayed-month)
272 (y1 displayed-year)
273 (m2 displayed-month)
274 (y2 displayed-year)
275 (year))
276 (increment-calendar-month m1 y1 -1)
277 (increment-calendar-month m2 y2 1)
278 (let* ((start-date (calendar-absolute-from-gregorian
279 (list m1 1 y1)))
280 (end-date (calendar-absolute-from-gregorian
281 (list m2 (calendar-last-day-of-month m2 y2) y2)))
282 (hebrew-start (calendar-hebrew-from-absolute start-date))
283 (hebrew-end (calendar-hebrew-from-absolute end-date))
284 (hebrew-y1 (extract-calendar-year hebrew-start))
285 (hebrew-y2 (extract-calendar-year hebrew-end)))
286 (setq year (if (< 6 month) hebrew-y2 hebrew-y1))
287 (let ((date (calendar-gregorian-from-absolute
288 (calendar-absolute-from-hebrew
289 (list month day year)))))
290 (if (calendar-date-is-visible-p date)
291 (list (list date string))))))))
292
293 (defun holiday-sexp (sexp string)
294 "Sexp holiday for dates in the calendar window.
295 SEXP is an expression in variable `year' evaluates to `date'.
296
297 STRING is an expression in `date' that evaluates to the holiday description
298 of `date'.
299
300 If `date' is visible in the calendar window, the holiday STRING is on that
301 date. If date is nil, or if the date is not visible, there is no holiday."
302 (let ((m displayed-month)
303 (y displayed-year))
304 (increment-calendar-month m y -1)
305 (filter-visible-calendar-holidays
306 (append
307 (let* ((year y)
308 (date (eval sexp))
309 (string (if date (eval string))))
310 (list (list date string)))
311 (let* ((year (1+ y))
312 (date (eval sexp))
313 (string (if date (eval string))))
314 (list (list date string)))))))
315
316 (defun holiday-advent ()
317 "Date of Advent, if visible in calendar window."
318 (let ((year displayed-year)
319 (month displayed-month))
320 (increment-calendar-month month year -1)
321 (let ((advent (calendar-gregorian-from-absolute
322 (calendar-dayname-on-or-before 0
323 (calendar-absolute-from-gregorian
324 (list 12 3 year))))))
325 (if (calendar-date-is-visible-p advent)
326 (list (list advent "Advent"))))))
327
328 (defun holiday-easter-etc ()
329 "List of dates related to Easter, as visible in calendar window."
330 (if (and (> displayed-month 5) (not all-christian-calendar-holidays))
331 nil;; Ash Wednesday, Good Friday, and Easter are not visible.
332 (let* ((century (1+ (/ displayed-year 100)))
333 (shifted-epact ;; Age of moon for April 5...
334 (% (+ 14 (* 11 (% displayed-year 19));; ...by Nicaean rule
335 (- ;; ...corrected for the Gregorian century rule
336 (/ (* 3 century) 4))
337 (/ ;; ...corrected for Metonic cycle inaccuracy.
338 (+ 5 (* 8 century)) 25)
339 (* 30 century));; Keeps value positive.
340 30))
341 (adjusted-epact ;; Adjust for 29.5 day month.
342 (if (or (= shifted-epact 0)
343 (and (= shifted-epact 1) (< 10 (% displayed-year 19))))
344 (1+ shifted-epact)
345 shifted-epact))
346 (paschal-moon ;; Day after the full moon on or after March 21.
347 (- (calendar-absolute-from-gregorian (list 4 19 displayed-year))
348 adjusted-epact))
349 (abs-easter (calendar-dayname-on-or-before 0 (+ paschal-moon 7)))
350 (mandatory
351 (list
352 (list (calendar-gregorian-from-absolute abs-easter)
353 "Easter Sunday")
354 (list (calendar-gregorian-from-absolute (- abs-easter 2))
355 "Good Friday")
356 (list (calendar-gregorian-from-absolute (- abs-easter 46))
357 "Ash Wednesday")))
358 (optional
359 (list
360 (list (calendar-gregorian-from-absolute (- abs-easter 63))
361 "Septuagesima Sunday")
362 (list (calendar-gregorian-from-absolute (- abs-easter 56))
363 "Sexagesima Sunday")
364 (list (calendar-gregorian-from-absolute (- abs-easter 49))
365 "Shrove Sunday")
366 (list (calendar-gregorian-from-absolute (- abs-easter 48))
367 "Shrove Monday")
368 (list (calendar-gregorian-from-absolute (- abs-easter 47))
369 "Shrove Tuesday")
370 (list (calendar-gregorian-from-absolute (- abs-easter 14))
371 "Passion Sunday")
372 (list (calendar-gregorian-from-absolute (- abs-easter 7))
373 "Palm Sunday")
374 (list (calendar-gregorian-from-absolute (- abs-easter 3))
375 "Maundy Thursday")
376 (list (calendar-gregorian-from-absolute (+ abs-easter 35))
377 "Rogation Sunday")
378 (list (calendar-gregorian-from-absolute (+ abs-easter 39))
379 "Ascension Day")
380 (list (calendar-gregorian-from-absolute (+ abs-easter 49))
381 "Pentecost (Whitsunday)")
382 (list (calendar-gregorian-from-absolute (+ abs-easter 50))
383 "Whitmunday")
384 (list (calendar-gregorian-from-absolute (+ abs-easter 56))
385 "Trinity Sunday")
386 (list (calendar-gregorian-from-absolute (+ abs-easter 60))
387 "Corpus Christi")))
388 (output-list
389 (filter-visible-calendar-holidays mandatory)))
390 (if all-christian-calendar-holidays
391 (setq output-list
392 (append
393 (filter-visible-calendar-holidays optional)
394 output-list)))
395 output-list)))
396
397 (defun holiday-greek-orthodox-easter ()
398 "Date of Easter according to the rule of the Council of Nicaea."
399 (let ((m displayed-month)
400 (y displayed-year))
401 (increment-calendar-month m y 1)
402 (let* ((julian-year
403 (extract-calendar-year
404 (calendar-julian-from-absolute
405 (calendar-absolute-from-gregorian
406 (list m (calendar-last-day-of-month m y) y)))))
407 (shifted-epact ;; Age of moon for April 5.
408 (% (+ 14
409 (* 11 (% julian-year 19)))
410 30))
411 (paschal-moon ;; Day after full moon on or after March 21.
412 (- (calendar-absolute-from-julian (list 4 19 julian-year))
413 shifted-epact))
414 (nicaean-easter;; Sunday following the Paschal moon
415 (calendar-gregorian-from-absolute
416 (calendar-dayname-on-or-before 0 (+ paschal-moon 7)))))
417 (if (calendar-date-is-visible-p nicaean-easter)
418 (list (list nicaean-easter "Pascha (Greek Orthodox Easter)"))))))
419
420 (defun holiday-rosh-hashanah-etc ()
421 "List of dates related to Rosh Hashanah, as visible in calendar window."
422 (if (or (< displayed-month 8)
423 (> displayed-month 11))
424 nil;; None of the dates is visible
425 (let* ((abs-r-h (calendar-absolute-from-hebrew
426 (list 7 1 (+ displayed-year 3761))))
427 (mandatory
428 (list
429 (list (calendar-gregorian-from-absolute abs-r-h)
430 (format "Rosh HaShanah %d" (+ 3761 displayed-year)))
431 (list (calendar-gregorian-from-absolute (+ abs-r-h 9))
432 "Yom Kippur")
433 (list (calendar-gregorian-from-absolute (+ abs-r-h 14))
434 "Sukkot")
435 (list (calendar-gregorian-from-absolute (+ abs-r-h 21))
436 "Shemini Atzeret")
437 (list (calendar-gregorian-from-absolute (+ abs-r-h 22))
438 "Simchat Torah")))
439 (optional
440 (list
441 (list (calendar-gregorian-from-absolute
442 (calendar-dayname-on-or-before 6 (- abs-r-h 4)))
443 "Selichot (night)")
444 (list (calendar-gregorian-from-absolute (1- abs-r-h))
445 "Erev Rosh HaShannah")
446 (list (calendar-gregorian-from-absolute (1+ abs-r-h))
447 "Rosh HaShanah (second day)")
448 (list (calendar-gregorian-from-absolute
449 (if (= (% abs-r-h 7) 4) (+ abs-r-h 3) (+ abs-r-h 2)))
450 "Tzom Gedaliah")
451 (list (calendar-gregorian-from-absolute
452 (calendar-dayname-on-or-before 6 (+ 7 abs-r-h)))
453 "Shabbat Shuvah")
454 (list (calendar-gregorian-from-absolute (+ abs-r-h 8))
455 "Erev Yom Kippur")
456 (list (calendar-gregorian-from-absolute (+ abs-r-h 13))
457 "Erev Sukkot")
458 (list (calendar-gregorian-from-absolute (+ abs-r-h 15))
459 "Sukkot (second day)")
460 (list (calendar-gregorian-from-absolute (+ abs-r-h 16))
461 "Hol Hamoed Sukkot (first day)")
462 (list (calendar-gregorian-from-absolute (+ abs-r-h 17))
463 "Hol Hamoed Sukkot (second day)")
464 (list (calendar-gregorian-from-absolute (+ abs-r-h 18))
465 "Hol Hamoed Sukkot (third day)")
466 (list (calendar-gregorian-from-absolute (+ abs-r-h 19))
467 "Hol Hamoed Sukkot (fourth day)")
468 (list (calendar-gregorian-from-absolute (+ abs-r-h 20))
469 "Hoshannah Rabbah")))
470 (output-list
471 (filter-visible-calendar-holidays mandatory)))
472 (if all-hebrew-calendar-holidays
473 (setq output-list
474 (append
475 (filter-visible-calendar-holidays optional)
476 output-list)))
477 output-list)))
478
479 (defun holiday-hanukkah ()
480 "List of dates related to Hanukkah, as visible in calendar window."
481 (if (memq displayed-month;; This test is only to speed things up a bit;
482 '(10 11 12 1 2));; it works fine without the test too.
483 (let ((m displayed-month)
484 (y displayed-year))
485 (increment-calendar-month m y 1)
486 (let* ((h-y (extract-calendar-year
487 (calendar-hebrew-from-absolute
488 (calendar-absolute-from-gregorian
489 (list m (calendar-last-day-of-month m y) y)))))
490 (abs-h (calendar-absolute-from-hebrew (list 9 25 h-y))))
491 (filter-visible-calendar-holidays
492 (list
493 (list (calendar-gregorian-from-absolute (1- abs-h))
494 "Erev Hanukkah")
495 (list (calendar-gregorian-from-absolute abs-h)
496 "Hanukkah (first day)")
497 (list (calendar-gregorian-from-absolute (1+ abs-h))
498 "Hanukkah (second day)")
499 (list (calendar-gregorian-from-absolute (+ abs-h 2))
500 "Hanukkah (third day)")
501 (list (calendar-gregorian-from-absolute (+ abs-h 3))
502 "Hanukkah (fourth day)")
503 (list (calendar-gregorian-from-absolute (+ abs-h 4))
504 "Hanukkah (fifth day)")
505 (list (calendar-gregorian-from-absolute (+ abs-h 5))
506 "Hanukkah (sixth day)")
507 (list (calendar-gregorian-from-absolute (+ abs-h 6))
508 "Hanukkah (seventh day)")
509 (list (calendar-gregorian-from-absolute (+ abs-h 7))
510 "Hanukkah (eighth day)")))))))
511
512 (defun holiday-passover-etc ()
513 "List of dates related to Passover, as visible in calendar window."
514 (if (< 7 displayed-month)
515 nil;; None of the dates is visible
516 (let* ((abs-p (calendar-absolute-from-hebrew
517 (list 1 15 (+ displayed-year 3760))))
518 (mandatory
519 (list
520 (list (calendar-gregorian-from-absolute abs-p)
521 "Passover")
522 (list (calendar-gregorian-from-absolute (+ abs-p 50))
523 "Shavuot")))
524 (optional
525 (list
526 (list (calendar-gregorian-from-absolute
527 (calendar-dayname-on-or-before 6 (- abs-p 43)))
528 "Shabbat Shekalim")
529 (list (calendar-gregorian-from-absolute
530 (calendar-dayname-on-or-before 6 (- abs-p 30)))
531 "Shabbat Zachor")
532 (list (calendar-gregorian-from-absolute
533 (if (= (% abs-p 7) 2) (- abs-p 33) (- abs-p 31)))
534 "Fast of Esther")
535 (list (calendar-gregorian-from-absolute (- abs-p 31))
536 "Erev Purim")
537 (list (calendar-gregorian-from-absolute (- abs-p 30))
538 "Purim")
539 (list (calendar-gregorian-from-absolute
540 (if (zerop (% abs-p 7)) (- abs-p 28) (- abs-p 29)))
541 "Shushan Purim")
542 (list (calendar-gregorian-from-absolute
543 (- (calendar-dayname-on-or-before 6 (- abs-p 14)) 7))
544 "Shabbat Parah")
545 (list (calendar-gregorian-from-absolute
546 (calendar-dayname-on-or-before 6 (- abs-p 14)))
547 "Shabbat HaHodesh")
548 (list (calendar-gregorian-from-absolute
549 (calendar-dayname-on-or-before 6 (1- abs-p)))
550 "Shabbat HaGadol")
551 (list (calendar-gregorian-from-absolute (1- abs-p))
552 "Erev Passover")
553 (list (calendar-gregorian-from-absolute (1+ abs-p))
554 "Passover (second day)")
555 (list (calendar-gregorian-from-absolute (+ abs-p 2))
556 "Hol Hamoed Passover (first day)")
557 (list (calendar-gregorian-from-absolute (+ abs-p 3))
558 "Hol Hamoed Passover (second day)")
559 (list (calendar-gregorian-from-absolute (+ abs-p 4))
560 "Hol Hamoed Passover (third day)")
561 (list (calendar-gregorian-from-absolute (+ abs-p 5))
562 "Hol Hamoed Passover (fourth day)")
563 (list (calendar-gregorian-from-absolute (+ abs-p 6))
564 "Passover (seventh day)")
565 (list (calendar-gregorian-from-absolute (+ abs-p 7))
566 "Passover (eighth day)")
567 (list (calendar-gregorian-from-absolute (+ abs-p 12))
568 "Yom HaShoah")
569 (list (calendar-gregorian-from-absolute
570 (if (zerop (% abs-p 7))
571 (+ abs-p 18)
572 (if (= (% abs-p 7) 6)
573 (+ abs-p 19)
574 (+ abs-p 20))))
575 "Yom HaAtzma'ut")
576 (list (calendar-gregorian-from-absolute (+ abs-p 33))
577 "Lag BaOmer")
578 (list (calendar-gregorian-from-absolute (+ abs-p 43))
579 "Yom Yerushalim")
580 (list (calendar-gregorian-from-absolute (+ abs-p 49))
581 "Erev Shavuot")
582 (list (calendar-gregorian-from-absolute (+ abs-p 51))
583 "Shavuot (second day)")))
584 (output-list
585 (filter-visible-calendar-holidays mandatory)))
586 (if all-hebrew-calendar-holidays
587 (setq output-list
588 (append
589 (filter-visible-calendar-holidays optional)
590 output-list)))
591 output-list)))
592
593 (defun holiday-tisha-b-av-etc ()
594 "List of dates around Tisha B'Av, as visible in calendar window."
595 (if (or (< displayed-month 5)
596 (> displayed-month 9))
597 nil;; None of the dates is visible
598 (let* ((abs-t-a (calendar-absolute-from-hebrew
599 (list 5 9 (+ displayed-year 3760)))))
600
601 (filter-visible-calendar-holidays
602 (list
603 (list (calendar-gregorian-from-absolute
604 (if (= (% abs-t-a 7) 6) (- abs-t-a 20) (- abs-t-a 21)))
605 "Tzom Tammuz")
606 (list (calendar-gregorian-from-absolute
607 (calendar-dayname-on-or-before 6 abs-t-a))
608 "Shabbat Hazon")
609 (list (calendar-gregorian-from-absolute
610 (if (= (% abs-t-a 7) 6) (1+ abs-t-a) abs-t-a))
611 "Tisha B'Av")
612 (list (calendar-gregorian-from-absolute
613 (calendar-dayname-on-or-before 6 (+ abs-t-a 7)))
614 "Shabbat Nahamu"))))))
615
616 (defun filter-visible-calendar-holidays (l)
617 "Return a list of all visible holidays of those on L."
618 (let ((visible)
619 (p l))
620 (while p
621 (and (car (car p))
622 (calendar-date-is-visible-p (car (car p)))
623 (setq visible (append (list (car p)) visible)))
624 (setq p (cdr p)))
625 visible))
626
627 (provide 'holidays)
628
629 ;;; holidays.el ends here