| blob | 0cafc85a24b4a54edcd48534200393a775b43f70 |
1 ;;; holidays.el --- holiday functions for the calendar package
3 ;; Copyright (C) 1989, 1990, 1992, 1993, 1994, 1997, 2001, 2002, 2003,
4 ;; 2004, 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
6 ;; Author: Edward M. Reingold <reingold@cs.uiuc.edu>
7 ;; Maintainer: Glenn Morris <rgm@gnu.org>
8 ;; Keywords: holidays, calendar
10 ;; This file is part of GNU Emacs.
12 ;; GNU Emacs is free software: you can redistribute it and/or modify
13 ;; it under the terms of the GNU General Public License as published by
14 ;; the Free Software Foundation, either version 3 of the License, or
15 ;; (at your option) any later version.
17 ;; GNU Emacs is distributed in the hope that it will be useful,
18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 ;; GNU General Public License for more details.
22 ;; You should have received a copy of the GNU General Public License
23 ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
25 ;;; Commentary:
27 ;; See calendar.el.
29 ;;; Code:
35 "Holidays support in calendar."
40 ;; The various holiday variables are autoloaded because people
41 ;; are used to using them to set calendar-holidays without having to
42 ;; explicitly load this file.
44 ;;;###autoload
64 "General holidays. Default value is for the United States.
65 See the documentation for `calendar-holidays' for details."
68 ;;;###autoload
70 ;;;###autoload
74 ;;;###autoload
87 ))))
88 "Oriental holidays.
89 See the documentation for `calendar-holidays' for details."
93 ;;;###autoload
95 ;;;###autoload
99 ;;;###autoload
101 "Local holidays.
102 See the documentation for `calendar-holidays' for details."
105 ;;;###autoload
107 ;;;###autoload
110 ;;;###autoload
112 "User defined holidays.
113 See the documentation for `calendar-holidays' for details."
116 ;;;###autoload
118 ;;;###autoload
121 ;;;###autoload
127 11
130 year)
136 22
139 ;;;###autoload
143 ;;;###autoload
149 10
161 ;;;###autoload
165 ;;;###autoload
170 11
192 day)
195 ;;;###autoload
199 ;;;###autoload
216 ;;;###autoload
220 ;;;###autoload
230 "Jewish holidays.
231 See the documentation for `calendar-holidays' for details."
235 ;;;###autoload
237 ;;;###autoload
241 ;;;###autoload
253 "Christian holidays.
254 See the documentation for `calendar-holidays' for details."
257 ;;;###autoload
259 ;;;###autoload
263 ;;;###autoload
277 "Islamic holidays.
278 See the documentation for `calendar-holidays' for details."
281 ;;;###autoload
283 ;;;###autoload
287 ;;;###autoload
301 "Baha'i holidays.
302 See the documentation for `calendar-holidays' for details."
305 ;;;###autoload
307 ;;;###autoload
310 ;;;###autoload
318 calendar-standard-time-zone-name)))
323 calendar-daylight-time-zone-name)))))
324 "Sun-related holidays.
325 See the documentation for `calendar-holidays' for details."
328 ;;;###autoload
330 ;;;###autoload
333 ;; This one should not be autoloaded, else .emacs changes of
334 ;; holiday-general-holidays etc have no effect.
335 ;; FIXME should have some :set-after.
338 holiday-other-holidays holiday-christian-holidays
339 holiday-hebrew-holidays holiday-islamic-holidays
340 holiday-bahai-holidays holiday-oriental-holidays
341 holiday-solar-holidays)
344 Additional holidays are easy to add to the list, just put them in the
345 list `holiday-other-holidays' in your .emacs file. Similarly, by setting
346 any of `holiday-general-holidays', `holiday-local-holidays',
347 `holiday-christian-holidays', `holiday-hebrew-holidays',
348 `holiday-islamic-holidays', `holiday-bahai-holidays',
349 `holiday-oriental-holidays', or `holiday-solar-holidays' to nil in your
350 .emacs file, you can eliminate unwanted categories of holidays.
352 The aforementioned variables control the holiday choices offered
353 by the function `holiday-list' when it is called interactively.
355 They also initialize the default value of `calendar-holidays',
356 which is the default list of holidays used by the function
357 `holiday-list' in the non-interactive case. Note that these
358 variables have no effect on `calendar-holidays' after it has been
359 set (e.g. after the calendar is loaded). In that case, customize
360 `calendar-holidays' directly.
362 The intention is that (in the US) `holiday-local-holidays' be set in
363 site-init.el and `holiday-other-holidays' be set by the user.
365 Entries on the list are expressions that return (possibly empty) lists of
366 items of the form ((month day year) string) of a holiday in the
367 three-month period centered around `displayed-month' of `displayed-year'.
368 Several basic functions are provided for this purpose:
370 (holiday-fixed MONTH DAY STRING) is a fixed date on the Gregorian calendar
371 (holiday-float MONTH DAYNAME K STRING &optional DAY) is the Kth DAYNAME
372 (0 for Sunday, etc.) after/before Gregorian
373 MONTH DAY. K<0 means count back from the end
374 of the month. Optional DAY defaults to 1 if
375 K>0, and MONTH's last day otherwise.
376 (holiday-hebrew MONTH DAY STRING) a fixed date on the Hebrew calendar
377 (holiday-islamic MONTH DAY STRING) a fixed date on the Islamic calendar
378 (holiday-bahai MONTH DAY STRING) a fixed date on the Baha'i calendar
379 (holiday-julian MONTH DAY STRING) a fixed date on the Julian calendar
380 (holiday-sexp SEXP STRING) SEXP is a Gregorian-date-valued expression
381 in the variable `year'; if it evaluates to
382 a visible date, that's the holiday; if it
383 evaluates to nil, there's no holiday. STRING
384 is an expression in the variable `date'.
386 For example, to add Bastille Day, celebrated in France on July 14, add
390 to the list. To add Hurricane Supplication Day, celebrated in the Virgin
391 Islands on the fourth Monday in August, add
395 to the list (the last Monday would be specified with `-1' instead of `4').
396 To add the last day of Hanukkah to the list, use
400 since the Hebrew months are numbered with 1 starting from Nisan.
401 To add the Islamic feast celebrating Mohammed's birthday, use
405 since the Islamic months are numbered from 1 starting with Muharram.
406 To add an entry for the Baha'i festival of Ridvan, use
410 since the Baha'i months are numbered from 1 starting with Baha.
411 To add Thomas Jefferson's birthday, April 2, 1743 (Julian), use
415 To include a holiday conditionally, use the sexp form or a conditional. For
416 example, to include American presidential elections, which occur on the first
417 Tuesday after the first Monday in November of years divisible by 4, add
419 (holiday-sexp
420 '(if (zerop (% year 4))
421 (calendar-gregorian-from-absolute
422 (1+ (calendar-dayname-on-or-before
423 1 (+ 6 (calendar-absolute-from-gregorian
424 (list 11 1 year)))))))
427 or
429 (if (zerop (% displayed-year 4))
430 (holiday-fixed 11
431 (calendar-extract-day
432 (calendar-gregorian-from-absolute
433 (1+ (calendar-dayname-on-or-before
434 1 (+ 6 (calendar-absolute-from-gregorian
435 (list 11 1 displayed-year)))))))
438 to the list. To include the phases of the moon, add
440 (lunar-phases)
442 to the holiday list, where `lunar-phases' is an Emacs-Lisp function that
443 you've written to return a (possibly empty) list of the relevant VISIBLE dates
444 with descriptive strings such as
449 ;;;###autoload
452 ;;; End of user options.
455 ;; FIXME name that makes sense
456 ;;;###diary-autoload
458 "Form the list of holidays that occur on dates in the calendar window.
459 The holidays are those in the list `calendar-holidays'."
477 ;; FIXME name that makes sense
478 ;;;###cal-autoload
480 "Create a buffer containing the holidays for the current calendar window.
481 The holidays are those in the list `calendar-notable-days'.
482 Returns non-nil if any holidays are found.
483 If EVENT is non-nil, it's an event indicating the buffer position to
484 use instead of point."
486 ;; If called from a menu, with the calendar window not selected.
513 holiday-list)))
518 ;;;###autoload
520 "Display the holidays for last month, this month, and next month.
521 If called with an optional prefix argument ARG, prompts for month and year.
522 This function is suitable for execution in a .emacs file."
532 ;; rms: "Emacs commands to display a list of something generally start
533 ;; with `list-'. Please make `list-holidays' the principal name."
534 ;;;###autoload
536 "Display holidays for years Y1 to Y2 (inclusive).
537 Y2 defaults to Y1. The optional list of holidays L defaults to
538 `calendar-holidays'. If you want to control what holidays are
539 displayed, use a different list. For example,
541 (list-holidays 2006 2006
542 (append holiday-general-holidays holiday-local-holidays))
544 will display holidays for the year 2006 defined in the two
545 mentioned lists, and nothing else.
547 When called interactively, this command offers a choice of
548 holidays, based on the variables `holiday-solar-holidays' etc. See the
549 documentation of `calendar-holidays' for a list of the variables
550 that control the choices, as well as a description of the format
551 of a holiday list.
553 The optional LABEL is used to label the buffer created."
556 "Starting year of holidays (>0): "
562 start-year)
596 choice
598 "Holidays"
609 holiday-list)
628 ;;;###autoload
631 ;;;###diary-autoload
633 "Check the list of holidays for any that occur on DATE.
634 The value returned is a list of strings of relevant holiday descriptions.
635 The holidays are those in the list `calendar-holidays'."
638 holiday-list)
648 ;;;###cal-autoload
650 "Find holidays for the date specified by the cursor in the calendar window.
651 Optional DATE is a list (month day year) to use instead of the
652 cursor position. EVENT specifies a buffer position to use for a date."
658 selection msg)
678 ;; FIXME move to calendar?
679 ;;;###cal-autoload
681 "Mark notable days in the calendar window.
682 If EVENT is non-nil, it's an event indicating the buffer position to
683 use instead of point."
685 ;; If called from a menu, with the calendar window not selected.
698 ;; Below are the functions that calculate the dates of holidays; these
699 ;; are eval'ed in the function calendar-holiday-list. If you
700 ;; write other such functions, be sure to imitate the style used below.
701 ;; Remember that each function must return a list of items of the form
702 ;; ((month day year) string) of VISIBLE dates in the calendar window.
705 "Holiday on MONTH, DAY (Gregorian) called STRING.
706 If MONTH, DAY is visible, the value returned is the list (((MONTH DAY year)
707 STRING)). Returns nil if it is not visible in the current calendar window."
708 ;; This determines whether a given month is visible in the calendar.
709 ;; cf calendar-date-is-visible-p (which also checks the year part).
710 ;; The day is irrelevant since only full months are displayed.
711 ;; Since the calendar displays three months at a time, month N
712 ;; is visible if displayed-month = N-1, N, N+1.
713 ;; In particular, November is visible if d-m = 10, 11, 12.
714 ;; This is useful, because we can do a one-sided test:
715 ;; November is visible if d-m > 9. (Similarly, February is visible if
716 ;; d-m < 4.)
717 ;; To determine if December is visible, we can shift the calendar
718 ;; back a month and ask if November is visible; to determine if
719 ;; October is visible, we can shift it forward a month and ask if
720 ;; November is visible; etc.
728 "Holiday called STRING on the Nth DAYNAME after/before MONTH DAY.
729 DAYNAME=0 means Sunday, DAYNAME=1 means Monday, and so on.
730 If N>0, use the Nth DAYNAME after MONTH DAY.
731 If N<0, use the Nth DAYNAME before MONTH DAY.
732 DAY defaults to 1 if N>0, and MONTH's last day otherwise.
733 If the holiday is visible in the calendar window, returns a
734 list (((month day year) STRING)). Otherwise returns nil."
735 ;; This is messy because the holiday may be visible, while the date
736 ;; on which it is based is not. For example, the first Monday after
737 ;; December 30 may be visible when January is not. For large values
738 ;; of |n| the problem is more grotesque. If we didn't have to worry
739 ;; about such cases, we could just use the original version of this
740 ;; function:
741 ;; (let ((m displayed-month)
742 ;; (y displayed-year))
743 ;; (calendar-increment-month m y (- 11 month))
744 ;; (if (> m 9); month in year y is visible
745 ;; (list (list (calendar-nth-named-day n dayname month y day) string)))))
765 y1
766 y2))
769 1
775 string)))))
778 "Filter list of holidays HLIST, and return only the visible ones.
779 HLIST is a list of elements of the form (DATE) TEXT."
782 hlist)))
788 "Sexp holiday for dates in the calendar window.
789 SEXP is an expression in variable `year' that is evaluated to
790 give `date'. STRING is an expression in `date' that evaluates to
791 the holiday description of `date'. If `date' is visible in the
792 calendar window, the holiday STRING is on that date. If date is
793 nil, or if the date is not visible, there is no holiday."
796 year date)
811 "Date of Nth day after advent (named STRING), if visible in calendar window.
812 Negative values of N are interpreted as days before advent.
813 STRING is used purely for display purposes. The return value has
814 the form ((MONTH DAY YEAR) STRING), where the date is that of the
815 Nth day before or after advent.
817 For backwards compatibility, if this function is called with no
818 arguments, then it returns the value appropriate for advent itself."
819 ;; Backwards compatibility layer.
827 (+ n
829 0
836 "Date of Nth day after Easter (named STRING), if visible in calendar window.
837 Negative values of N are interpreted as days before Easter.
838 STRING is used purely for display purposes. The return value has
839 the form ((MONTH DAY YEAR) STRING), where the date is that of the
840 Nth day before or after Easter.
842 For backwards compatibility, if this function is called with no
844 holidays (with more entries if `calendar-christian-all-holidays-flag'
845 is non-nil)."
846 ;; Backwards compatibility layer.
851 ;; The combined list is not in order.
884 shifted-epact))
887 adjusted-epact))
893 ;; Prior call to calendar-julian-from-absolute will autoload cal-julian.
897 "Date of Easter according to the rule of the Council of Nicaea."
912 shifted-epact))
921 ;; arch-tag: 48eb3117-75a7-4dbe-8fd9-873c3cbb0d37
922 ;;; holidays.el ends here