;;; holidays.el --- holiday functions for the calendar package
-;; Copyright (C) 1989, 90, 92, 93, 94, 1997 Free Software Foundation, Inc.
+;; Copyright (C) 1989, 1990, 1992, 1993, 1994, 1997, 2001, 2002, 2003,
+;; 2004, 2005, 2006 Free Software Foundation, Inc.
;; Author: Edward M. Reingold <reingold@cs.uiuc.edu>
+;; Maintainer: Glenn Morris <rgm@gnu.org>
;; Keywords: holidays, calendar
;; This file is part of GNU Emacs.
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING. If not, write to the
-;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-;; Boston, MA 02111-1307, USA.
+;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+;; Boston, MA 02110-1301, USA.
;;; Commentary:
;; in calendar.el.
;; Technical details of all the calendrical calculations can be found in
-;; ``Calendrical Calculations'' by Nachum Dershowitz and Edward M. Reingold,
-;; Cambridge University Press (1997).
+;; ``Calendrical Calculations: The Millennium Edition'' by Edward M. Reingold
+;; and Nachum Dershowitz, Cambridge University Press (2001).
;; An earlier version of the technical details appeared in
;; ``Calendrical Calculations'' by Nachum Dershowitz and Edward M. Reingold,
"Holiday on MONTH, DAY (Islamic) called STRING."
t)
+(autoload 'holiday-bahai "cal-bahai"
+ "Holiday on MONTH, DAY (Baha'i) called STRING."
+ t)
+
(autoload 'holiday-chinese-new-year "cal-china"
"Date of Chinese New Year."
t)
(defun list-holidays (y1 y2 &optional l label)
"Display holidays for years Y1 to Y2 (inclusive).
-The optional list of holidays L defaults to `calendar-holidays'. See the
-documentation for that variable for a description of holiday lists.
+The optional list of holidays L defaults to `calendar-holidays'.
+If you want to control what holidays are displayed, use a
+different list. For example,
+
+ (list-holidays 2006 2006
+ (append general-holidays local-holidays other-holidays))
+
+will display holidays for the year 2006 defined in the 3
+mentioned lists, and nothing else.
+
+When called interactively, this command offers a choice of
+holidays, based on the variables `solar-holidays' etc. See the
+documentation of `calendar-holidays' for a list of the variables
+that control the choices, as well as a description of the format
+of a holiday list.
The optional LABEL is used to label the buffer created."
(interactive
(if christian-holidays (cons "Christian" christian-holidays))
(if hebrew-holidays (cons "Hebrew" hebrew-holidays))
(if islamic-holidays (cons "Islamic" islamic-holidays))
+ (if bahai-holidays (cons "Baha'i" bahai-holidays))
(if oriental-holidays (cons "Oriental" oriental-holidays))
(if solar-holidays (cons "Solar" solar-holidays))
(cons "Ask" nil)))
(string (if date (eval string))))
(list (list date string)))))))
-(defun holiday-advent ()
- "Date of Advent, if visible in calendar window."
- (let ((year displayed-year)
- (month displayed-month))
- (increment-calendar-month month year -1)
- (let ((advent (calendar-gregorian-from-absolute
- (calendar-dayname-on-or-before 0
- (calendar-absolute-from-gregorian
- (list 12 3 year))))))
- (if (calendar-date-is-visible-p advent)
- (list (list advent "Advent"))))))
-
-(defun holiday-easter-etc ()
- "List of dates related to Easter, as visible in calendar window."
- (if (and (> displayed-month 5) (not all-christian-calendar-holidays))
- nil;; Ash Wednesday, Good Friday, and Easter are not visible.
- (let* ((century (1+ (/ displayed-year 100)))
- (shifted-epact ;; Age of moon for April 5...
- (% (+ 14 (* 11 (% displayed-year 19));; ...by Nicaean rule
- (- ;; ...corrected for the Gregorian century rule
- (/ (* 3 century) 4))
- (/ ;; ...corrected for Metonic cycle inaccuracy.
- (+ 5 (* 8 century)) 25)
- (* 30 century));; Keeps value positive.
- 30))
- (adjusted-epact ;; Adjust for 29.5 day month.
- (if (or (= shifted-epact 0)
- (and (= shifted-epact 1) (< 10 (% displayed-year 19))))
- (1+ shifted-epact)
- shifted-epact))
- (paschal-moon ;; Day after the full moon on or after March 21.
- (- (calendar-absolute-from-gregorian (list 4 19 displayed-year))
- adjusted-epact))
- (abs-easter (calendar-dayname-on-or-before 0 (+ paschal-moon 7)))
- (mandatory
- (list
- (list (calendar-gregorian-from-absolute abs-easter)
- "Easter Sunday")
- (list (calendar-gregorian-from-absolute (- abs-easter 2))
- "Good Friday")
- (list (calendar-gregorian-from-absolute (- abs-easter 46))
- "Ash Wednesday")))
- (optional
- (list
- (list (calendar-gregorian-from-absolute (- abs-easter 63))
- "Septuagesima Sunday")
- (list (calendar-gregorian-from-absolute (- abs-easter 56))
- "Sexagesima Sunday")
- (list (calendar-gregorian-from-absolute (- abs-easter 49))
- "Shrove Sunday")
- (list (calendar-gregorian-from-absolute (- abs-easter 48))
- "Shrove Monday")
- (list (calendar-gregorian-from-absolute (- abs-easter 47))
- "Shrove Tuesday")
- (list (calendar-gregorian-from-absolute (- abs-easter 14))
- "Passion Sunday")
- (list (calendar-gregorian-from-absolute (- abs-easter 7))
- "Palm Sunday")
- (list (calendar-gregorian-from-absolute (- abs-easter 3))
- "Maundy Thursday")
- (list (calendar-gregorian-from-absolute (+ abs-easter 35))
- "Rogation Sunday")
- (list (calendar-gregorian-from-absolute (+ abs-easter 39))
- "Ascension Day")
- (list (calendar-gregorian-from-absolute (+ abs-easter 49))
- "Pentecost (Whitsunday)")
- (list (calendar-gregorian-from-absolute (+ abs-easter 50))
- "Whitmonday")
- (list (calendar-gregorian-from-absolute (+ abs-easter 56))
- "Trinity Sunday")
- (list (calendar-gregorian-from-absolute (+ abs-easter 60))
- "Corpus Christi")))
- (output-list
- (filter-visible-calendar-holidays mandatory)))
- (if all-christian-calendar-holidays
- (setq output-list
- (append
- (filter-visible-calendar-holidays optional)
- output-list)))
- output-list)))
+(defun holiday-advent (&optional n string)
+ "Date of Nth day after advent (named STRING), if visible in calendar window.
+Negative values of N are interpreted as days before advent.
+STRING is used purely for display purposes. The return value has
+the form ((MONTH DAY YEAR) STRING), where the date is that of the
+Nth day before or after advent.
+
+For backwards compatibility, if this function is called with no
+arguments, then it returns the value appropriate for advent itself."
+ ;; Backwards compatibility layer.
+ (if (not n)
+ (holiday-advent 0 "Advent")
+ (let ((year displayed-year)
+ (month displayed-month))
+ (increment-calendar-month month year -1)
+ (let ((advent (calendar-gregorian-from-absolute
+ (+ n
+ (calendar-dayname-on-or-before
+ 0
+ (calendar-absolute-from-gregorian
+ (list 12 3 year)))))))
+ (if (calendar-date-is-visible-p advent)
+ (list (list advent string)))))))
+
+(defun holiday-easter-etc (&optional n string)
+ "Date of Nth day after Easter (named STRING), if visible in calendar window.
+Negative values of N are interpreted as days before Easter.
+STRING is used purely for display purposes. The return value has
+the form ((MONTH DAY YEAR) STRING), where the date is that of the
+Nth day before or after Easter.
+
+For backwards compatibility, if this function is called with no
+arguments, then it returns a list of \"standard\" Easter-related
+holidays (with more entries if `all-christian-calendar-holidays'
+is non-nil)."
+ ;; Backwards compatibility layer.
+ (if (not n)
+ (let (res-list res)
+ (dolist (elem (append
+ (if all-christian-calendar-holidays
+ '((-63 . "Septuagesima Sunday")
+ (-56 . "Sexagesima Sunday")
+ (-49 . "Shrove Sunday")
+ (-48 . "Shrove Monday")
+ (-47 . "Shrove Tuesday")
+ (-14 . "Passion Sunday")
+ (-7 . "Palm Sunday")
+ (-3 . "Maundy Thursday")
+ (35 . "Rogation Sunday")
+ (39 . "Ascension Day")
+ (49 . "Pentecost (Whitsunday)")
+ (50 . "Whitmonday")
+ (56 . "Trinity Sunday")
+ (60 . "Corpus Christi")))
+ '((0 . "Easter Sunday")
+ (-2 . "Good Friday")
+ (-46 . "Ash Wednesday")))
+ res-list)
+ ;; Filter out nil (not visible) values.
+ (if (setq res (holiday-easter-etc (car elem) (cdr elem)))
+ (setq res-list (append res res-list)))))
+ (let* ((century (1+ (/ displayed-year 100)))
+ (shifted-epact ;; Age of moon for April 5...
+ (% (+ 14 (* 11 (% displayed-year 19)) ;; ...by Nicaean rule
+ (- ;; ...corrected for the Gregorian century rule
+ (/ (* 3 century) 4))
+ (/ ;; ...corrected for Metonic cycle inaccuracy.
+ (+ 5 (* 8 century)) 25)
+ (* 30 century)) ;; Keeps value positive.
+ 30))
+ (adjusted-epact ;; Adjust for 29.5 day month.
+ (if (or (zerop shifted-epact)
+ (and (= shifted-epact 1) (< 10 (% displayed-year 19))))
+ (1+ shifted-epact)
+ shifted-epact))
+ (paschal-moon ;; Day after the full moon on or after March 21.
+ (- (calendar-absolute-from-gregorian (list 4 19 displayed-year))
+ adjusted-epact))
+ (abs-easter (calendar-dayname-on-or-before 0 (+ paschal-moon 7))))
+ (filter-visible-calendar-holidays
+ (list (list (calendar-gregorian-from-absolute (+ abs-easter n))
+ string))))))
(defun holiday-greek-orthodox-easter ()
"Date of Easter according to the rule of the Council of Nicaea."