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1 ;;; holidays.el --- holiday functions for the calendar package
3 ;; Copyright (C) 1989-1990, 1992-1994, 1997, 2001-2011
4 ;; Free Software Foundation, Inc.
6 ;; Author: Edward M. Reingold <reingold@cs.uiuc.edu>
7 ;; Maintainer: Glenn Morris <rgm@gnu.org>
8 ;; Keywords: holidays, calendar
9 ;; Package: calendar
11 ;; This file is part of GNU Emacs.
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
15 ;; the Free Software Foundation, either version 3 of the License, or
16 ;; (at your option) any later version.
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.
23 ;; You should have received a copy of the GNU General Public License
24 ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
26 ;;; Commentary:
28 ;; See calendar.el.
30 ;;; Code:
36 "Holidays support in calendar."
41 ;; The various holiday variables are autoloaded because people
42 ;; are used to using them to set calendar-holidays without having to
43 ;; explicitly load this file.
45 ;;;###autoload
48 ;;;###autoload
68 "General holidays. Default value is for the United States.
69 See the documentation for `calendar-holidays' for details."
72 ;;;###autoload
75 ;;;###autoload
78 ;;;###autoload
91 ))))
92 "Oriental holidays.
93 See the documentation for `calendar-holidays' for details."
97 ;;;###autoload
100 ;;;###autoload
102 ;;;###autoload
104 "Local holidays.
105 See the documentation for `calendar-holidays' for details."
108 ;;;###autoload
111 ;;;###autoload
113 ;;;###autoload
115 "User defined holidays.
116 See the documentation for `calendar-holidays' for details."
119 ;;;###autoload
122 ;;;###autoload
128 11
131 year)
137 22
140 ;;;###autoload
144 ;;;###autoload
150 10
162 ;;;###autoload
166 ;;;###autoload
171 11
193 day)
196 ;;;###autoload
200 ;;;###autoload
217 ;;;###autoload
221 ;;;###autoload
224 ;;;###autoload
234 "Jewish holidays.
235 See the documentation for `calendar-holidays' for details."
239 ;;;###autoload
242 ;;;###autoload
245 ;;;###autoload
257 "Christian holidays.
258 See the documentation for `calendar-holidays' for details."
261 ;;;###autoload
264 ;;;###autoload
267 ;;;###autoload
281 "Islamic holidays.
282 See the documentation for `calendar-holidays' for details."
285 ;;;###autoload
288 ;;;###autoload
290 ;;;###autoload
304 "Baha'i holidays.
305 See the documentation for `calendar-holidays' for details."
308 ;;;###autoload
311 ;;;###autoload
313 ;;;###autoload
321 calendar-standard-time-zone-name)))
326 calendar-daylight-time-zone-name)))))
327 "Sun-related holidays.
328 See the documentation for `calendar-holidays' for details."
331 ;;;###autoload
334 ;; This one should not be autoloaded, else .emacs changes of
335 ;; holiday-general-holidays etc have no effect.
336 ;; FIXME should have some :set-after.
339 holiday-other-holidays holiday-christian-holidays
340 holiday-hebrew-holidays holiday-islamic-holidays
341 holiday-bahai-holidays holiday-oriental-holidays
342 holiday-solar-holidays)
345 Additional holidays are easy to add to the list, just put them in the
346 list `holiday-other-holidays' in your .emacs file. Similarly, by setting
347 any of `holiday-general-holidays', `holiday-local-holidays',
348 `holiday-christian-holidays', `holiday-hebrew-holidays',
349 `holiday-islamic-holidays', `holiday-bahai-holidays',
350 `holiday-oriental-holidays', or `holiday-solar-holidays' to nil in your
351 .emacs file, you can eliminate unwanted categories of holidays.
353 The aforementioned variables control the holiday choices offered
354 by the function `holiday-list' when it is called interactively.
356 They also initialize the default value of `calendar-holidays',
357 which is the default list of holidays used by the function
358 `holiday-list' in the non-interactive case. Note that these
359 variables have no effect on `calendar-holidays' after it has been
360 set (e.g. after the calendar is loaded). In that case, customize
361 `calendar-holidays' directly.
363 The intention is that (in the US) `holiday-local-holidays' be set in
364 site-init.el and `holiday-other-holidays' be set by the user.
366 Entries on the list are expressions that return (possibly empty) lists of
367 items of the form ((month day year) string) of a holiday in the
368 three-month period centered around `displayed-month' of `displayed-year'.
369 Several basic functions are provided for this purpose:
371 (holiday-fixed MONTH DAY STRING) is a fixed date on the Gregorian calendar
372 (holiday-float MONTH DAYNAME K STRING &optional DAY) is the Kth DAYNAME
373 (0 for Sunday, etc.) after/before Gregorian
374 MONTH DAY. K<0 means count back from the end
375 of the month. Optional DAY defaults to 1 if
376 K>0, and MONTH's last day otherwise.
377 (holiday-hebrew MONTH DAY STRING) a fixed date on the Hebrew calendar
378 (holiday-islamic MONTH DAY STRING) a fixed date on the Islamic calendar
379 (holiday-bahai MONTH DAY STRING) a fixed date on the Baha'i calendar
380 (holiday-julian MONTH DAY STRING) a fixed date on the Julian calendar
381 (holiday-sexp SEXP STRING) SEXP is a Gregorian-date-valued expression
382 in the variable `year'; if it evaluates to
383 a visible date, that's the holiday; if it
384 evaluates to nil, there's no holiday. STRING
385 is an expression in the variable `date'.
387 For example, to add Bastille Day, celebrated in France on July 14, add
391 to the list. To add Hurricane Supplication Day, celebrated in the Virgin
392 Islands on the fourth Monday in August, add
396 to the list (the last Monday would be specified with `-1' instead of `4').
397 To add the last day of Hanukkah to the list, use
401 since the Hebrew months are numbered with 1 starting from Nisan.
402 To add the Islamic feast celebrating Mohammed's birthday, use
406 since the Islamic months are numbered from 1 starting with Muharram.
407 To add an entry for the Baha'i festival of Ridvan, use
411 since the Baha'i months are numbered from 1 starting with Baha.
412 To add Thomas Jefferson's birthday, April 2, 1743 (Julian), use
416 To include a holiday conditionally, use the sexp form or a conditional. For
417 example, to include American presidential elections, which occur on the first
418 Tuesday after the first Monday in November of years divisible by 4, add
420 (holiday-sexp
421 '(if (zerop (% year 4))
422 (calendar-gregorian-from-absolute
423 (1+ (calendar-dayname-on-or-before
424 1 (+ 6 (calendar-absolute-from-gregorian
425 (list 11 1 year)))))))
428 or
430 (if (zerop (% displayed-year 4))
431 (holiday-fixed 11
432 (calendar-extract-day
433 (calendar-gregorian-from-absolute
434 (1+ (calendar-dayname-on-or-before
435 1 (+ 6 (calendar-absolute-from-gregorian
436 (list 11 1 displayed-year)))))))
439 to the list. To include the phases of the moon, add
441 (lunar-phases)
443 to the holiday list, where `lunar-phases' is an Emacs-Lisp function that
444 you've written to return a (possibly empty) list of the relevant VISIBLE dates
445 with descriptive strings such as
450 ;;;###autoload
453 ;;; End of user options.
456 ;; FIXME name that makes sense
457 ;;;###diary-autoload
459 "Form the list of holidays that occur on dates in the calendar window.
460 The holidays are those in the list `calendar-holidays'."
478 ;; FIXME name that makes sense
479 ;;;###cal-autoload
481 "Create a buffer containing the holidays for the current calendar window.
482 The holidays are those in the list `calendar-notable-days'.
483 Returns non-nil if any holidays are found.
484 If EVENT is non-nil, it's an event indicating the buffer position to
485 use instead of point."
487 ;; If called from a menu, with the calendar window not selected.
514 holiday-list)))
519 ;;;###autoload
521 "Display the holidays for last month, this month, and next month.
522 If called with an optional prefix argument ARG, prompts for month and year.
523 This function is suitable for execution in a .emacs file."
533 ;; rms: "Emacs commands to display a list of something generally start
534 ;; with `list-'. Please make `list-holidays' the principal name."
535 ;;;###autoload
537 "Display holidays for years Y1 to Y2 (inclusive).
538 Y2 defaults to Y1. The optional list of holidays L defaults to
539 `calendar-holidays'. If you want to control what holidays are
540 displayed, use a different list. For example,
542 (list-holidays 2006 2006
543 (append holiday-general-holidays holiday-local-holidays))
545 will display holidays for the year 2006 defined in the two
546 mentioned lists, and nothing else.
548 When called interactively, this command offers a choice of
549 holidays, based on the variables `holiday-solar-holidays' etc. See the
550 documentation of `calendar-holidays' for a list of the variables
551 that control the choices, as well as a description of the format
552 of a holiday list.
554 The optional LABEL is used to label the buffer created."
557 "Starting year of holidays (>0): "
563 start-year)
597 choice
599 "Holidays"
610 holiday-list)
629 ;;;###autoload
632 ;;;###diary-autoload
634 "Check the list of holidays for any that occur on DATE.
635 DATE is a list (month day year). This function considers the
636 holidays from the list `calendar-holidays', and returns a list of
637 strings describing those holidays that apply on DATE."
640 holiday-list)
650 ;;;###cal-autoload
652 "Find holidays for the date specified by the cursor in the calendar window.
653 Optional DATE is a list (month day year) to use instead of the
654 cursor position. EVENT specifies a buffer position to use for a date."
660 selection msg)
680 ;; FIXME move to calendar?
681 ;;;###cal-autoload
683 "Mark notable days in the calendar window.
684 If EVENT is non-nil, it's an event indicating the buffer position to
685 use instead of point."
687 ;; If called from a menu, with the calendar window not selected.
700 ;; Below are the functions that calculate the dates of holidays; these
701 ;; are eval'ed in the function calendar-holiday-list. If you
702 ;; write other such functions, be sure to imitate the style used below.
703 ;; Remember that each function must return a list of items of the form
704 ;; ((month day year) string) of VISIBLE dates in the calendar window.
707 "Holiday on MONTH, DAY (Gregorian) called STRING.
708 If MONTH, DAY is visible, the value returned is the list (((MONTH DAY year)
709 STRING)). Returns nil if it is not visible in the current calendar window."
710 ;; This determines whether a given month is visible in the calendar.
711 ;; cf calendar-date-is-visible-p (which also checks the year part).
712 ;; The day is irrelevant since only full months are displayed.
713 ;; Since the calendar displays three months at a time, month N
714 ;; is visible if displayed-month = N-1, N, N+1.
715 ;; In particular, November is visible if d-m = 10, 11, 12.
716 ;; This is useful, because we can do a one-sided test:
717 ;; November is visible if d-m > 9. (Similarly, February is visible if
718 ;; d-m < 4.)
719 ;; To determine if December is visible, we can shift the calendar
720 ;; back a month and ask if November is visible; to determine if
721 ;; October is visible, we can shift it forward a month and ask if
722 ;; November is visible; etc.
730 "Holiday called STRING on the Nth DAYNAME after/before MONTH DAY.
731 DAYNAME=0 means Sunday, DAYNAME=1 means Monday, and so on.
732 If N>0, use the Nth DAYNAME after MONTH DAY.
733 If N<0, use the Nth DAYNAME before MONTH DAY.
734 DAY defaults to 1 if N>0, and MONTH's last day otherwise.
735 If the holiday is visible in the calendar window, returns a
736 list (((month day year) STRING)). Otherwise returns nil."
737 ;; This is messy because the holiday may be visible, while the date
738 ;; on which it is based is not. For example, the first Monday after
739 ;; December 30 may be visible when January is not. For large values
740 ;; of |n| the problem is more grotesque. If we didn't have to worry
741 ;; about such cases, we could just use the original version of this
742 ;; function:
743 ;; (let ((m displayed-month)
744 ;; (y displayed-year))
745 ;; (calendar-increment-month m y (- 11 month))
746 ;; (if (> m 9); month in year y is visible
747 ;; (list (list (calendar-nth-named-day n dayname month y day) string)))))
767 y1
768 y2))
771 1
777 string)))))
780 "Filter list of holidays HLIST, and return only the visible ones.
781 HLIST is a list of elements of the form (DATE) TEXT."
784 hlist)))
790 "Sexp holiday for dates in the calendar window.
791 SEXP is an expression in variable `year' that is evaluated to
792 give `date'. STRING is an expression in `date' that evaluates to
793 the holiday description of `date'. If `date' is visible in the
794 calendar window, the holiday STRING is on that date. If date is
795 nil, or if the date is not visible, there is no holiday."
798 year date)
813 "Date of Nth day after advent (named STRING), if visible in calendar window.
814 Negative values of N are interpreted as days before advent.
815 STRING is used purely for display purposes. The return value has
816 the form ((MONTH DAY YEAR) STRING), where the date is that of the
817 Nth day before or after advent.
819 For backwards compatibility, if this function is called with no
820 arguments, then it returns the value appropriate for advent itself."
821 ;; Backwards compatibility layer.
829 (+ n
831 0
838 "Date of Nth day after Easter (named STRING), if visible in calendar window.
839 Negative values of N are interpreted as days before Easter.
840 STRING is used purely for display purposes. The return value has
841 the form ((MONTH DAY YEAR) STRING), where the date is that of the
842 Nth day before or after Easter.
844 For backwards compatibility, if this function is called with no
846 holidays (with more entries if `calendar-christian-all-holidays-flag'
847 is non-nil)."
848 ;; Backwards compatibility layer.
853 ;; The combined list is not in order.
886 shifted-epact))
889 adjusted-epact))
895 ;; Prior call to calendar-julian-from-absolute will autoload cal-julian.
899 "Date of Easter according to the rule of the Council of Nicaea."
914 shifted-epact))
923 ;;; holidays.el ends here