reingold@m.cs.uiuc.edu (12/26/89)
The first three responses to this message contain, respectively, the files
calendar.el, diary.el, and holidays.el. These files are also available by
anonymous ftp to a.cs.uiuc.edu in pub/calendar. You need all three of them
for the calendar to work properly.
Here are some of the highlights, compared to the old calendar.el in prior
postings to this news group:
* All known bugs have been fixed.
* There is now an "include" mechanism to enable `shared diary files'.
* Diary entry styles are now controlled by a list of patterns, so that
European-style dates are now an option. (But the form of the patterns
no longer permits a DAY entry--you must use the `*'.)
* Two-digit abbreviated years are now acceptable in diary entries.
* Added the `C' calendar command for the ISO commercial calendar.
* Added the `D' calendar command to give the day in the Gregorian year
(current day's number and the number of days remaining).
* Display style of dates is now controlled by a pattern.
* The Hebrew calendar functions have been rewritten to make them
much faster; this makes holiday determination much faster.
* The holiday determination is now much more general.
* The code has been split into three files: the calendar stuff is in the
main file, calendar.el; the diary stuff is in diary.el; the holiday
stuff is in holiday.el.
* A diary hook example has been added that shows how to get sorted diary
entries in the fancy diary buffer.reingold@m.cs.uiuc.edu (12/26/89)
;; Diary functions.
;; Copyright (C) 1989, 1990 Free Software Foundation, Inc.
;; This file is part of GNU Emacs.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY. No author or distributor
;; accepts responsibility to anyone for the consequences of using it
;; or for whether it serves any particular purpose or works at all,
;; unless he says so in writing. Refer to the GNU Emacs General Public
;; License for full details.
;; Everyone is granted permission to copy, modify and redistribute
;; GNU Emacs, but only under the conditions described in the
;; GNU Emacs General Public License. A copy of this license is
;; supposed to have been given to you along with GNU Emacs so you
;; can know your rights and responsibilities. It should be in a
;; file named COPYING. Among other things, the copyright notice
;; and this notice must be preserved on all copies.
;; This collection of functions implements the diary features as described
;; in calendar.el.
;; Comments, corrections, and improvements should be sent to
;; Edward M. Reingold Department of Computer Science
;; (217) 333-6733 University of Illinois at Urbana-Champaign
;; reingold@cs.uiuc.edu 1304 West Springfield Avenue
;; Urbana, Illinois 61801
(require 'calendar)
(provide 'diary)
(defun diary (&optional arg)
"Generate the diary window for ARG days starting with the current date.
If no argument is provided, the number of days of diary entries is governed
by the variable `number-of-diary-entries'. This function is suitable for
execution in a .emacs file."
(interactive "P")
(if (and diary-file (file-exists-p diary-file))
(if (file-readable-p diary-file)
(let ((date (calendar-current-date)))
(list-diary-entries
date
(cond
(arg (prefix-numeric-value arg))
((vectorp number-of-diary-entries)
(aref number-of-diary-entries (calendar-day-of-week date)))
(t number-of-diary-entries))))
(error "Your diary file is not readable!"))
(error "You don't have a diary file!")))
(defun view-diary-entries (arg)
"Prepare and display a buffer with diary entries.
Searches the file diary-file for entries that match ARG days starting with
the date indicated by the cursor position in the displayed three-month
calendar."
(interactive "p")
(if (and diary-file (file-exists-p diary-file))
(if (file-readable-p diary-file)
(list-diary-entries (or (calendar-cursor-to-date)
(error "Cursor is not on a date!"))
arg)
(error "Your diary file is not readable!"))
(error "You don't have a diary file!")))
(autoload 'check-calendar-holidays "holidays"
"Check the list of holidays for any that occur on DATE.
The value returned is a list of strings of relevant holiday descriptions.
The holidays are those in the list calendar-holidays.")
(defun list-diary-entries (date number &optional nomessage)
"Create and display a buffer containing the relevant lines in diary-file.
All lines that apply to DATE and the next NUMBER-1 days are included.
If the optional NOMESSAGE is t, the diary is generated silently.
Returns a list of all relevant diary entries found, if any, in order by date.
The list entries have the form ((month day year) string). If the variable
`diary-list-include-blanks' is t, this list will include a dummy diary entry
(consisting of the empty string) for a date with no diary entries. Also
prepared is a list of holidays for DATE, if `holidays-in-diary-buffer' is t.
After the lists is prepared, the hooks `list-diary-entries-hook' are run."
(if (< 0 number)
(progn
(or nomessage
(message "Preparing diary..."))
(let* ((original-date date);; save for possible use in the hooks
(diary-entries-list)
(date-string (calendar-date-string date))
(holiday-string
(mapconcat
'identity
(if holidays-in-diary-buffer
(check-calendar-holidays date))
"; ")))
(save-excursion
(let ((diary-buffer (get-file-buffer diary-file)))
(set-buffer (if diary-buffer
diary-buffer
(find-file-noselect diary-file t))))
(setq selective-display t)
(setq selective-display-ellipses nil)
(make-local-variable 'mode-line-format)
(setq mode-line-format
(concat "%*--"
(if (string-equal holiday-string "")
"---------------"
"")
"Diary "
(if (string-equal holiday-string "")
"entries for "
"for ")
date-string
(if (string-equal holiday-string "")
""
": ")
holiday-string
"%-"))
(let ((buffer-read-only nil)
(diary-modified (buffer-modified-p))
(mark (regexp-quote diary-nonmarking-symbol)))
(goto-char (1- (point-max)))
(if (not (looking-at "\^M\\|\n"))
(progn
(forward-char 1)
(insert-string "\^M")))
(goto-char (point-min))
(if (not (looking-at "\^M\\|\n"))
(insert-string "\^M"))
(subst-char-in-region (point-min) (point-max) ?\n ?\^M t)
(calendar-for-loop i from 1 to number do
(let ((d diary-date-forms)
(month (extract-calendar-month date))
(day (extract-calendar-day date))
(year (extract-calendar-year date))
(entry-found))
(while d
(let*
((date-form (car d))
(dayname
(concat
(calendar-day-name date) "\\|"
(substring (calendar-day-name date) 0 3) ".?"))
(monthname
(concat
"\\*\\|"
(calendar-month-name month) "\\|"
(substring (calendar-month-name month) 0 3) ".?"))
(month (concat "\\*\\|0*" (int-to-string month)))
(day (concat "\\*\\|0*" (int-to-string day)))
(year
(concat
"\\*\\|0*" (int-to-string year)
(if abbreviated-calendar-year
(concat "\\|" (int-to-string (mod year 100)))
"")))
(regexp
(concat
"\\(\\`\\|\^M\\|\n\\)" mark "?\\("
(mapconcat
'(lambda (x) (if (stringp x) x (eval x)))
date-form "\\)\\(")
"\\)"))
(case-fold-search t))
(goto-char (point-min))
(while (re-search-forward regexp nil t)
(if (and (or (char-equal (preceding-char) ?\^M)
(char-equal (preceding-char) ?\n))
(not (looking-at " \\|\^I")))
nil;; Empty diary entry that consists only of date.
;; Found a nonempty diary entry--make it visible and
;; add it to the list.
(setq entry-found t)
(let ((entry-start (point))
(date-start))
(re-search-backward "\^M\\|\n\\|\\`")
(setq date-start (point))
(re-search-forward "\^M\\|\n" nil t 2)
(while (looking-at " \\|\^I")
(re-search-forward "\^M\\|\n" nil t))
(backward-char 1)
(subst-char-in-region date-start (point) ?\^M ?\n t)
(setq diary-entries-list
(append
diary-entries-list
(list
(list date
(buffer-substring
entry-start
(point))))))))))
(setq d (cdr d)))
(or entry-found
(not diary-list-include-blanks)
(setq diary-entries-list
(append diary-entries-list
(list (list date "")))))
(setq date
(calendar-gregorian-from-absolute
(1+ (calendar-absolute-from-gregorian date))))
(setq month (extract-calendar-month date))
(setq day (extract-calendar-day date))
(setq year (extract-calendar-year date))
(setq entry-found nil)))
(set-buffer-modified-p diary-modified))
(goto-char (point-min))
(run-hooks 'list-diary-entries-hook)
diary-entries-list)))))
(defun include-other-diary-files ()
"Include the diary entries from other diary files with those of diary-file.
This function is suitable for use just before prepare-fancy-diary-buffer as
the list-dairy-entries-hook; it enables you to use shared diary files together
with your own. The files included are specified in the diary-file by lines
of the form
#include \"filename\"
This is recursive; that is, #include directives in diary files thus included
are obeyed. You can change the \"#include\" to some other string by
changing the variable `diary-include-string'."
(goto-char (point-min))
(while (re-search-forward
(concat
"\\(\\`\\|\^M\\|\n\\)"
(regexp-quote diary-include-string)
" \"\\([^\"]*\\)\"")
nil t)
(let ((diary-file (buffer-substring (match-beginning 2) (match-end 2)))
(diary-list-include-blanks nil)
(list-diary-entries-hook 'include-other-diary-files))
(if (file-exists-p diary-file)
(if (file-readable-p diary-file)
(progn
(setq diary-entries-list
(append diary-entries-list
(list-diary-entries original-date number t)))
(kill-buffer (get-file-buffer diary-file)))
(beep)
(message "Can't read included diary file %s" diary-file)
(sleep-for 2))
(beep)
(message "Can't find included diary file %s" diary-file)
(sleep-for 2))))
(goto-char (point-min)))
(defun prepare-fancy-diary-buffer ()
"Prepare a diary buffer with relevant entries in a fancy, noneditable form.
This function is provided for optional use as the `list-diary-entries-hook'."
(if (or (not diary-entries-list)
(and (not (cdr diary-entries-list))
(string-equal (car (cdr (car diary-entries-list))) "")))
(message "No diary entries for %s %s" date-string holiday-string)
(save-excursion;; Turn off selective-display in the diary file's buffer.
(set-buffer (get-file-buffer diary-file))
(let ((diary-modified (buffer-modified-p)))
(subst-char-in-region (point-min) (point-max) ?\^M ?\n t)
(setq selective-display nil)
(kill-local-variable 'mode-line-format)
(set-buffer-modified-p diary-modified)))
(save-excursion;; Prepare the fancy diary buffer.
(set-buffer (get-buffer-create fancy-diary-buffer))
(setq buffer-read-only nil)
(make-local-variable 'mode-line-format)
(setq mode-line-format "---------------------------Diary Entries%-")
(erase-buffer)
(let ((entry-list diary-entries-list)
(date (list 0 0 0)))
(while entry-list
(if (not (calendar-date-equal date (car (car entry-list))))
(progn
(setq date (car (car entry-list)))
(let* ((date-string (calendar-date-string date))
(holiday-string
(mapconcat
'identity
(if holidays-in-diary-buffer
(check-calendar-holidays date))
"; ")))
(insert (if (= (point) (point-min)) "" ?\n) date-string)
(if (< 0 (length holiday-string))
(insert ": " holiday-string))
(let ((l (current-column)))
(insert ?\n (make-string l ?=) ?\n)))))
(if (< 0 (length (car (cdr (car entry-list)))))
(insert (car (cdr (car entry-list))) ?\n))
(setq entry-list (cdr entry-list))))
(set-buffer-modified-p nil)
(goto-char (point-min))
(setq buffer-read-only t)
(message "Preparing diary...done")
(display-buffer fancy-diary-buffer))))
(defun print-diary-entries ()
"Print a hard copy of the entries visible in the diary window.
The hooks given by the variable `print-diary-entries-hook' are called after
the temporary buffer of visible diary entries is prepared; it is the hooks
that do the actual printing and kill the buffer."
(interactive)
(let ((diary-buffer (get-file-buffer diary-file)))
(if diary-buffer
(let ((temp-buffer (get-buffer-create "*Printable Diary Entries*")))
(save-excursion
(set-buffer diary-buffer)
(copy-to-buffer temp-buffer (point-min) (point-max))
(set-buffer temp-buffer)
(while (re-search-forward "\^M.*$" nil t)
(replace-match ""))
(run-hooks 'print-diary-entries-hook)))
(error "You don't have a diary buffer!"))))
(defun add-diary-heading ()
"Add a heading to the diary entries for printing.
The heading is formed from the mode line of the diary buffer. This function
is used in the default value of the variable `print-diary-entry-hooks'."
(save-excursion
(let ((heading))
(set-buffer diary-buffer)
(setq heading mode-line-format)
(string-match "%\\*-*\\([^-].*\\)%-$" heading)
(setq heading
(substring heading (match-beginning 1) (match-end 1)))
(set-buffer temp-buffer)
(goto-char (point-min))
(insert heading "\n"
(make-string (length heading) ?=) "\n"))))
(defun show-all-diary-entries ()
"Show all of the diary entries in the diary-file.
This function gets rid of the selective display of the diary-file so that
all entries, not just some, are visible. If there is no diary buffer, one
is created."
(interactive)
(if (and diary-file (file-exists-p diary-file))
(if (file-readable-p diary-file)
(save-excursion
(let ((diary-buffer (get-file-buffer diary-file)))
(set-buffer (if diary-buffer
diary-buffer
(find-file-noselect diary-file t)))
(let ((buffer-read-only nil)
(diary-modified (buffer-modified-p)))
(subst-char-in-region (point-min) (point-max) ?\^M ?\n t)
(setq selective-display nil)
(make-local-variable 'mode-line-format)
(setq mode-line-format
(concat "%*---------------------------All Diary Entries%-"))
(display-buffer (current-buffer))
(set-buffer-modified-p diary-modified))))
(error "Your diary file is not readable!"))
(error "You don't have a diary file!")))
(defun diary-name-pattern (string-array)
"Convert an array of strings to a pattern.
The pattern will match any of the strings, either entirely or abbreviated
to three characters. An abbreviated form will match with or without a period."
(let ((pattern ""))
(calendar-for-loop i from 0 to (1- (length string-array)) do
(setq pattern
(concat
pattern (if (string-equal pattern "") "" "\\|")
(aref string-array i) "\\|"
(substring (aref string-array i) 0 3) ".?")))
pattern))
(defun mark-diary-entries ()
"Mark days in the calendar window that have diary entries.
Each entry in diary-file visible in the calendar window is marked. After the
entries are marked, the hooks `mark-diary-entries-hook' are run."
(interactive)
(if (and diary-file (file-exists-p diary-file))
(if (file-readable-p diary-file)
(save-excursion
(message "Marking diary entries...")
(set-buffer (find-file-noselect diary-file t))
(let ((d diary-date-forms))
(while d
(let*
((date-form (car d))
(dayname (diary-name-pattern calendar-day-name-array))
(monthname
(concat
(diary-name-pattern calendar-month-name-array)
"\\|\\*"))
(month "[0-9]+\\|\\*")
(day "[0-9]+\\|\\*")
(year "[0-9]+\\|\\*")
(l (length date-form))
(d-name-pos (- l (length (memq 'dayname date-form))))
(d-name-pos (if (/= l d-name-pos) (+ 2 d-name-pos)))
(m-name-pos (- l (length (memq 'monthname date-form))))
(m-name-pos (if (/= l m-name-pos) (+ 2 m-name-pos)))
(d-pos (- l (length (memq 'day date-form))))
(d-pos (if (/= l d-pos) (+ 2 d-pos)))
(m-pos (- l (length (memq 'month date-form))))
(m-pos (if (/= l m-pos) (+ 2 m-pos)))
(y-pos (- l (length (memq 'year date-form))))
(y-pos (if (/= l y-pos) (+ 2 y-pos)))
(regexp
(concat
"\\(\\`\\|\^M\\|\n\\)\\("
(mapconcat
'(lambda (x) (if (stringp x) x (eval x)))
date-form "\\)\\(")
"\\)"))
(case-fold-search t))
(goto-char (point-min))
(while (re-search-forward regexp nil t)
(let* ((dd-name
(if d-name-pos
(buffer-substring
(match-beginning d-name-pos)
(match-end d-name-pos))))
(mm-name
(if m-name-pos
(buffer-substring
(match-beginning m-name-pos)
(match-end m-name-pos))))
(mm (string-to-int
(if m-pos
(buffer-substring
(match-beginning m-pos)
(match-end m-pos))
"")))
(dd (string-to-int
(if d-pos
(buffer-substring
(match-beginning d-pos)
(match-end d-pos))
"")))
(y-str (if y-pos
(buffer-substring
(match-beginning y-pos)
(match-end y-pos))))
(yy (if (not y-str)
0
(if (and (= (length y-str) 2)
abbreviated-calendar-year)
(let* ((current-y
(extract-calendar-year
(calendar-current-date)))
(y (+ (string-to-int y-str)
(* 100 (/ current-y 100)))))
(if (> (- y current-y) 50)
(- y 100)
(if (> (- current-y y) 50)
(+ y 100)
y)))
(string-to-int y-str)))))
(if dd-name
(mark-calendar-days-named
(cdr (assoc (capitalize (substring dd-name 0 3))
calendar-day-abbrev-list)))
(if mm-name
(if (string-equal mm-name "*")
(setq mm 0)
(setq mm
(cdr (assoc
(capitalize (substring mm-name 0 3))
calendar-month-abbrev-list)))))
(mark-calendar-date-pattern mm dd yy))))
(setq d (cdr d)))))
(run-hooks 'mark-diary-entries-hook)
(message "Marking diary entries...done"))
(error "Your diary file is not readable!"))
(error "You don't have a diary file!")))
(defun mark-included-diary-files ()
"Mark the diary entries from other diary files with those of diary-file.
This function is suitable for use as the mark-dairy-entries-hook; it enables
you to use shared diary files together with your own. The files included are
specified in the diary-file by lines of the form
#include \"filename\"
This is recursive; that is, #include directives in diary files thus included
are obeyed. You can change the \"#include\" to some other string by
changing the variable `diary-include-string'."
(goto-char (point-min))
(while (re-search-forward
(concat
"\\(\\`\\|\^M\\|\n\\)"
(regexp-quote diary-include-string)
" \"\\([^\"]*\\)\"")
nil t)
(let ((diary-file (buffer-substring (match-beginning 2) (match-end 2)))
(mark-diary-entries-hook 'mark-included-diary-files))
(if (file-exists-p diary-file)
(if (file-readable-p diary-file)
(progn
(mark-diary-entries)
(kill-buffer (get-file-buffer diary-file)))
(beep)
(message "Can't read included diary file %s" diary-file)
(sleep-for 2))
(beep)
(message "Can't find included diary file %s" diary-file)
(sleep-for 2))))
(goto-char (point-min)))
(defun mark-calendar-days-named (dayname)
"Mark all dates in the calendar window that are day DAYNAME of the week.
0 means all Sundays, 1 means all Mondays, and so on."
(save-excursion
(set-buffer calendar-buffer)
(let ((prev-month displayed-month)
(prev-year displayed-year)
(succ-month displayed-month)
(succ-year displayed-year)
(last-day)
(day))
(increment-calendar-month succ-month succ-year 1)
(increment-calendar-month prev-month prev-year -1)
(setq day (calendar-absolute-from-gregorian
(calendar-nth-named-day 1 dayname prev-month prev-year)))
(setq last-day (calendar-absolute-from-gregorian
(calendar-nth-named-day -1 dayname succ-month succ-year)))
(while (<= day last-day)
(mark-visible-calendar-date (calendar-gregorian-from-absolute day))
(setq day (+ day 7))))))
(defun mark-calendar-date-pattern (month day year)
"Mark all dates in the calendar window that conform to MONTH/DAY/YEAR.
A value of 0 in any position is a wild-card."
(save-excursion
(set-buffer calendar-buffer)
(let ((m displayed-month)
(y displayed-year))
(increment-calendar-month m y -1)
(calendar-for-loop i from 0 to 2 do
(mark-calendar-month m y month day year)
(increment-calendar-month m y 1)))))
(defun mark-calendar-month (month year p-month p-day p-year)
"Mark dates in the MONTH/YEAR that conform to pattern P-MONTH/P_DAY/P-YEAR.
A value of 0 in any position of the pattern is a wild-card."
(if (or (and (= month p-month)
(or (= p-year 0) (= year p-year)))
(and (= p-month 0)
(or (= p-year 0) (= year p-year))))
(if (= p-day 0)
(calendar-for-loop
i from 1 to (calendar-last-day-of-month month year) do
(mark-visible-calendar-date (list month i year)))
(mark-visible-calendar-date (list month p-day year)))))
(defun diary-entry-compare (e1 e2)
"Returns t if E1 is earlier than E2."
(or (calendar-date-compare e1 e2)
(and (calendar-date-equal (car e1) (car e2))
(string-lessp (car (cdr e1)) (car (cdr e2))))))reingold@m.cs.uiuc.edu (12/26/89)
;; Calendar functions.
;; Copyright (C) 1988, 1989, 1990 Free Software Foundation, Inc.
;; This file is part of GNU Emacs.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY. No author or distributor
;; accepts responsibility to anyone for the consequences of using it
;; or for whether it serves any particular purpose or works at all,
;; unless he says so in writing. Refer to the GNU Emacs General Public
;; License for full details.
;; Everyone is granted permission to copy, modify and redistribute
;; GNU Emacs, but only under the conditions described in the
;; GNU Emacs General Public License. A copy of this license is
;; supposed to have been given to you along with GNU Emacs so you
;; can know your rights and responsibilities. It should be in a
;; file named COPYING. Among other things, the copyright notice
;; and this notice must be preserved on all copies.
;; This collection of functions implements a calendar window. It generates
;; generates a calendar for the current month, together with the previous and
;; coming months, or for any other three-month period. The calendar can be
;; shifted forward and backward in the window to show months in the past or
;; future; the cursor can move forward and backward by days, weeks, or months,
;; making it possible, for instance, to jump to the date a specified number of
;; days, weeks, or months from the date under the cursor. The user can
;; display a list of holidays and other notable days for the period shown; the
;; notable days can be marked on the calendar, if desired. The user can also
;; specify that dates having corresponding diary entries (in a file that the
;; user specifies) be marked; the diary entries for any date can be viewed in
;; a separate window. The diary and the notable days can be viewed
;; independently of the calendar. Dates can be translated from the (usual)
;; Gregorian calendar to the day of the year/days remaining in year, to the
;; ISO commercial calendar, to the Julian (old style) calendar, to the Hebrew
;; calendar, and to the Islamic calendar.
;; The diary related functions are in diary.el; the holiday related functions
;; are in holiday.el
;; Comments, corrections, and improvements should be sent to
;; Edward M. Reingold Department of Computer Science
;; (217) 333-6733 University of Illinois at Urbana-Champaign
;; reingold@cs.uiuc.edu 1304 West Springfield Avenue
;; Urbana, Illinois 61801
;; GNU Emacs users too numerous to list pointed out a variety of problems
;; with earlier forms of the `infinite' sliding calendar and suggested some
;; of the features included in this package. Especially significant in this
;; regard was the suggestion of mark-diary-entries and view-diary-entries,
;; together ideas for their implementation, by
;; Michael S. Littman Cognitive Science Research Group
;; (201)-829-5155 Bell Communications Research
;; mlittman@wind.bellcore.com 445 South St. Box 1961 (2L-331)
;; Morristown, NJ 07960-1961
;; The algorithms for the Hebrew calendar are those of the Rambam (Rabbi Moses
;; Maimonides), from his Mishneh Torah, as implemented by
;; Nachum Dershowitz Department of Computer Science
;; (217) 333-4219 University of Illinois at Urbana-Champaign
;; nachum@cs.uiuc.edu 1304 West Springfield Avenue
;; Urbana, Illinois 61801
;; Technical details of all the calendrical calculations can be found in
;; ``Calendrical Calculations'' by Edward M. Reingold and Nachum Dershowitz,
;; Report Number UIUCDCS-R-89-1541, Department of Computer Science,
;; University of Illinois, Urbana, Illinois, September, 1989.
(provide 'calendar)
(defvar view-diary-entries-initially nil
"*If T, the diary entries for the current date will be displayed on entry.
The diary is displayed in another window when the calendar is first displayed,
if the current date is visible. The number of days of diary entries displayed
is governed by the variable `number-of-diary-entries'.")
(defvar number-of-diary-entries 1
"*Specifies how many days of diary entries are to be displayed initially.
This variable affects the diary display when the command M-x diary is used,
or if the value of the variable `view-diary-entries-initially' is t. For
example, if the default value 1 is used, then only the current day's diary
entries will be displayed. If the value 2 is used, then both the current
day's and the next day's entries will be displayed. The value can also be
a vector such as [0 2 2 2 2 4 1]; this value will cause no diary entries to
be displayed on Sunday, the current date's and the next day's diary entries
to be displayed Monday through Thursday, Friday through Monday's entries to
be displayed on Friday, and only Saturday's entries to be displayed on
Saturday. This variable does not affect the diary display with the `d'
command from the calendar; in that case, the prefix argument controls the
number of days of diary entries displayed.")
(defvar mark-diary-entries-in-calendar nil
"*If t, dates with diary entries will be marked in the calendar window.
The marking symbol is specifed by the variable `diary-entry-marker'.")
(defvar diary-entry-marker "+"
"*The symbol used to mark dates that have diary entries.")
(defvar view-calendar-holidays-initially nil
"*If t, the holidays for the current three month period will be displayed
on entry. The holidays are displayed in another window when the calendar is
first displayed.")
(defvar mark-holidays-in-calendar nil
"*If t, dates of holidays will be marked in the calendar window.
The marking symbol is specified by the variable `calendar-holiday-marker'.")
(defvar calendar-holiday-marker "*"
"*The symbol used to mark notable dates in the calendar.")
(defvar initial-calendar-window-hook nil
"*List of functions to be called when the calendar window is first opened.
The functions invoked are called after the calendar window is opened, but
once opened is never called again. Leaving the calendar with the `q' command
and reentering it will cause these functions to be called again.")
(defvar today-visible-calendar-hook nil
"*List of functions called whenever the current date is visible.
This can be used, for example, to replace today's date with asterisks; a
function `calendar-star-date' is included for this purpose:
(setq today-visible-calendar-hook 'calendar-star-date)
It could also be used to mark the current date with `*'; a function is also
provided for this:
(setq today-visible-calendar-hook 'calendar-mark-today)
The corresponding variable `today-invisible-calendar-hook' is the list of
functions called when the calendar function was called when the current
date is not visible in the window.
Other than the use of the provided functions, the changing of any
characters in the calendar buffer by the hooks may cause the failure of the
functions that move by days and weeks.")
(defvar today-invisible-calendar-hook nil
"*List of functions called whenever the current date is not visible.
The corresponding variable `today-visible-calendar-hook' is the list of
functions called when the calendar function was called when the current
date is visible in the window.
Other than the use of the provided functions, the changing of any
characters in the calendar buffer by the hooks may cause the failure of the
functions that move by days and weeks.")
(defvar diary-file "~/diary"
"*Name of the file in which one's personal diary of dates is kept.
The file's entries are lines in any of the forms
MONTH/DAY
MONTH/DAY/YEAR
MONTHNAME DAY
MONTHNAME DAY, YEAR
DAYNAME
at the beginning of the line; the remainder of the line is the diary entry
string for that date. MONTH and DAY are one or two digit numbers, YEAR is
a number and may be written in full or abbreviated to the final two digits.
If the date does not contain a year, it is generic and applies to any year.
DAYNAME entries apply to any date on which is on that day of the week.
MONTHNAME and DAYNAME can be spelled in full, abbreviated to three
characters (with or without a period), capitalized or not. Any of DAY,
MONTH, or MONTHNAME, YEAR can be `*' which matches any day, month, or year,
respectively.
The European style (in which the day precedes the month) can be used
instead, if you set `european-calendar-style' to t.
A diary entry can be preceded by a diary-nonmarking-symbol (ordinarily `&')
to make that entry nonmarking--that is, it will not be marked on dates in
the calendar window but will appear in a diary window.
Multiline diary entries are made by indenting lines after the first with
either a TAB or one or more spaces.
Lines not in one the above formats are ignored. Here are some sample diary
entries:
12/22/1988 Twentieth wedding anniversary!!
&1/1. Happy New Year!
10/22 Ruth's birthday.
21: Payday
Tuesday--weekly meeting with grad students at 10am
Supowit, Shen, Bitner, and Kapoor to attend.
1/13/89 Friday the thirteenth!!
&thu 4pm squash game with Lloyd.
mar 16 Dad's birthday
April 15, 1989 Income tax due.
&* 15 time cards due.
If the first line of a diary entry consists only of the date or day name with
no trailing blanks or punctuation, then that line will not be displayed in the
diary window; only the continuation lines will be shown. For example, the
single diary entry
02/11/1989
Bill Blattner visits Princeton today
2pm Cognitive Studies Committee meeting
2:30-5:30 Lizzie at Lawrenceville for `Group Initiative'
4:00pm Jamie Tappenden
7:30pm Dinner at George and Ed's for Alan Ryan
7:30-10:00pm dance at Stewart Country Day School
will appear in the diary window without the date line at the beginning. This
facility allows the diary window to look neater, but can cause confusion if
used with more than one day's entries displayed.
Diary files can contain directives to include the contents of other files; for
details, see the documentation for the variable `list-diary-entries-hook'.")
(defvar diary-nonmarking-symbol "&"
"*The symbol used to indicate that a diary entry is not to be marked in the
calendar window.")
(defvar diary-include-string "#include"
"*The string used to indicate the inclusion of another file of diary entries
in diary-file. See the documentation for the function
`include-other-diary-files'.")
(defvar abbreviated-calendar-year t
"*Interpret a two-digit year DD in a diary entry as being either 19DD or
20DD, as appropriate. If this variable is nil, years must be written in
full.")
(defvar european-calendar-style nil
"*Use the European style of dates in the diary and in any displays. If this
variable is t, a date 1/2/1990 would be interpretted as February 2, 1990.
The accepted European date styles are
DAY/MONTH
DAY/MONTH/YEAR
DAY MONTHNAME
DAY MONTHNAME, YEAR
DAYNAME
Names can be capitalized or not, written in full, or abbreviated to three
characters with or without a period.")
(defvar diary-date-forms
(if european-calendar-style
'((day "/" month "[^/0-9]")
(day "/" month "/" year "[^0-9]")
(day " *" monthname "[^,]")
(day " *" monthname ", *" year "[^0-9]")
(dayname "\\W*"))
'((month "/" day "[^/0-9]")
(month "/" day "/" year "[^0-9]")
(monthname " *" day "[^,0-9]")
(monthname " *" day ", *" year "[^0-9]")
(dayname "\\W*")))
"*List of pseudo-patterns describing the forms of date used in the diary.
The patterns on the list must be MUTUALLY EXCLUSIVE and must NOT match any
portion of the diary entry itself, just the date component. The keyword
`monthname' will match the name of the month, capitalized or not, or its
three-letter abbreviation, followed by a period or not; it will also match
`*'. Similarly, `dayname' will match the name of the day, capitalized or not,
or its three-letter abbreviation, followed by a period or not. The keywords
`month', `day', and `year' will match those numerical values, preceded by
arbitrarily many zeros; they will also match `*'.")
(defvar calendar-date-display-form
(if european-calendar-style
'(dayname ", " day " " monthname ", " year)
'(dayname ", " monthname " " day ", " year))
"*The pseudo-pattern that governs the way a date is formatted as a string by
the function `calendar-date-string'. The recognized keywords are `month',
`day', and `year', all numbers in string form, and `monthname' and `dayname'
(alphabetic strings). For example, the ISO standard would use the pseudo-
pattern '(year \"-\" month \"-\" day), while the usual American form would be
'(month \"/\" day \"/\" (substring year -2)). See the documentation of the
function `calendar-date-string'.")
(defvar print-diary-entries-hook
'(add-diary-heading lpr-buffer (lambda nil (kill-buffer temp-buffer)))
"*List of functions to be called after a temporary buffer is prepared
with the diary entries currently visible in the diary buffer. The default
value adds a heading (formed from the information in the mode line of the
diary buffer), does the printing, and kills the buffer. Other uses might
include, for example, rearranging the lines into order by day and time,
saving the buffer instead of deleting it, or changing the function used to
do the printing.")
(defvar list-diary-entries-hook
'(lambda nil
(if (not diary-entries-list)
(message "No diary entries for %s %s" date-string holiday-string)
(message "Preparing diary...done")
(display-buffer (get-file-buffer diary-file))))
"*List of functions to be called after the diary buffer is prepared.
Ordinarily, this just displays the diary buffer (with holidays indicated in
the mode line), if there are any relevant entries. At the time these
functions are called, the variable `diary-entries-list' is a list, in order
by date, of all relevant diary entries in the form of ((MONTH DAY YEAR)
STRING), where string is the diary entry for the given date. This can be
used, for example, to handle appointment notification, prepare a different
buffer for display (perhaps combined with holidays), or produce hard copy
output.
A function `prepare-fancy-diary-buffer' is provided as an alternative
choice for this hook; this function prepares a special noneditable diary
buffer with the relevant diary entries that has neat day-by-day arrangement
with headings. The fancy diary buffer will show the holidays unless the
variable `holidays-in-diary-buffer' is set to nil. Ordinarily, the fancy
diary buffer will not show days for which there are no diary entries, even
if that day is a holiday; if you want such days to be shown in the fancy
diary buffer, set the variable `diary-list-include-blanks' to t.
A function `include-other-diary-files' is also provided. This function is
suitable for use just before `prepare-fancy-diary-buffer' as the
`list-diary-entries-hook'; it enables you to use shared diary files together
with your own. The files included are specified in the diary-file by lines
of the form
#include \"filename\"
This is recursive; that is, #include directives in files thus included are
obeyed. You can change the \"#include\" to some other string by changing
the variable `diary-include-string'. When you use `include-other-diary-files'
as part of the list-diary-entries-hook, you will probably also want to use the
function `mark-included-diary-files' as part of the mark-diary-entries-hook.
For example, you could use
(setq list-diary-entries-hook
'(include-other-diary-files
(lambda nil
(setq diary-entries-list
(sort diary-entries-list 'diary-entry-compare)))
prepare-fancy-diary-buffer))
in your .emacs file to cause the fancy diary buffer to be displayed with
diary entries from various included files, each day's entries sorted into
lexicographic order.")
(defvar mark-diary-entries-hook nil
"*List of functions called after marking diary entries in the calendar.
A function `mark-included-diary-files' is also provided for use as the
mark-dairy-entries-hook; it enables you to use shared diary files together
with your own. The files included are specified in the diary-file by lines
of the form
#include \"filename\"
This is recursive; that is, #include directives in files thus included are
obeyed. You can change the \"#include\" to some other string by changing the
variable `diary-include-string'. When you use `mark-included-diary-files' as
part of the mark-diary-entries-hook, you will probably also want to use the
function `include-other-diary-files' as part of the list-diary-entries-hook.")
(defvar diary-list-include-blanks nil
"*If nil, do not include days with no diary entry in the list of diary
entries. Such days will then not be shown in the the fancy diary buffer,
even if they are holidays.")
(defvar holidays-in-diary-buffer t
"*If t, the holidays will be indicated in the mode line of the diary buffer
(or in the fancy diary buffer next to the date). This slows down the diary
functions somewhat; setting it to nil will make the diary display faster.")
(defvar calendar-holidays
'((fixed 1 1 "New Year's Day")
(float 1 1 3 "Martin Luther King Day")
(fixed 2 2 "Ground Hog Day")
(fixed 2 14 "Valentine's Day")
(float 2 1 3 "President's Day")
(hebrew (hebrew-calendar-last-month-of-year (+ displayed-year 3760))
14
"Purim")
(fixed 3 17 "St. Patrick's Day")
(easter-etc)
(fixed 4 1 "April Fool's Day")
(hebrew 1 15 "Passover")
(float 4 0 1 "Daylight Savings Time Begins")
(float 5 0 2 "Mother's Day")
(float 5 1 -1 "Memorial Day")
(hebrew 3 6 "Shavuoth")
(fixed 6 14 "Flag Day")
(float 6 0 3 "Father's Day")
(fixed 7 4 "Independence Day")
(hebrew 5
(if (= (mod (calendar-absolute-from-hebrew
(list 5 9 (+ displayed-year 3760)))
7)
6)
10 9)
"Tisha B'Av")
(float 9 1 1 "Labor Day")
(rosh-hashanah-etc)
(float 10 1 2 "Columbus Day")
(float 10 0 -1 "Daylight Savings Time Ends")
(fixed 10 31 "Halloween")
(fixed 11 11 "Veteran's Day")
(float 11 4 4 "Thanksgiving")
(hebrew 9 25 "Hanukah")
(fixed 12 25 "Christmas")
(julian 12 25 "Eastern Orthodox Christmas")
(islamic 1 1 (format "Islamic New Year %d"
(let ((m displayed-month)
(y displayed-year))
(increment-calendar-month m y 1)
(extract-calendar-year
(calendar-islamic-from-absolute
(calendar-absolute-from-gregorian
(list m (calendar-last-day-of-month m y) y)))))))
(islamic 9 1 "Ramadan Begins"))
"List of notable days for the command M-x holidays.
Additional holidays are easy to add to the list. The possible forms are
(fixed MONTH DAY STRING) a fixed date on the Gregorian calendar
(float MONTH DAYNAME K STRING) the Kth DAYNAME in MONTH on the Gregorian
calendar (0 for Sunday, etc.); K<0 means
count back from the end of the month
(hebrew MONTH DAY STRING) a fixed date on the Hebrew calendar
(islamic MONTH DAY STRING) a fixed date on the Islamic calendar
(julian MONTH DAY STRING) a fixed date on the Julian calendar
(FUNCTION &optional ARGS) dates requiring special computation; ARGS,
if any, are passed in a list to the function
`calendar-holiday-function-FUNCTION'
For example, to add Bastille Day, July 14, add
(fixed 7 14 \"Bastille Day\")
to the list. To add Irish Bank Day, the first Monday in June, add
(float 6 2 1 \"Irish Bank Day\")
to the list (the last Monday would be specified with `-1' instead of `1').
To add the last day of Hanukah to the list, use
(hebrew 10 2 \"Last day of Hanukah\")
since the Hebrew months are numbered with 1 starting from Nisan, while to
add the Islamic feast celebrating Mohammed's birthday use
(islamic 3 12 \"Mohammed's Birthday\")
since the Islamic months are numbered from 1 starting with Muharram. To
add Thomas Jefferson's birthday, April 2, 1743 (Julian), use
(julian 4 2 \"Jefferson's Birthday\")
while to include the phases of the moon, add
(lunar-phases)
to the holiday list, where `calendar-holiday-function-lunar-phases' is an
Emacs-Lisp function that you've written to return a (possibly empty) list of
the relevant VISIBLE dates with descriptive strings such as
(((2 6 1989) \"New Moon\") ((2 12 1989) \"First Quarter Moon\") ... )
In fact, the fixed, float, hebrew, islamic, and julian forms are implemented by
the inclusion of the functions `calendar-holiday-function-fixed',
`calendar-holiday-function-float', `calendar-holiday-function-hebrew',
`calendar-holiday-function-islamic', and `calendar-holiday-function-julian',
respectively.")
(defconst calendar-buffer "*Calendar*"
"Name of the buffer used for the calendar.")
(defconst holiday-buffer "*Holidays*"
"Name of the buffer used for the displaying the holidays.")
(defconst fancy-diary-buffer "*Fancy Diary Entries*"
"Name of the buffer used for the optional fancy display of the diary.")
(defmacro increment-calendar-month (mon yr n)
"Move the variables MON and YR to the month and year N months forward
if N is positive or backward if N is negative."
(` (let (( macro-y (+ (* (, yr) 12) (, mon) -1 (, n) )))
(setq (, mon) (1+ (mod macro-y 12) ))
(setq (, yr) (/ macro-y 12)))))
(defmacro calendar-for-loop (var from init to final do &rest body)
"Execute a for loop."
(` (let (( (, var) (1- (, init)) ))
(while (>= (, final) (setq (, var) (1+ (, var))))
(,@ body)))))
(defmacro calendar-sum (index initial condition expression)
"For INDEX = INITIAL and successive integers, as long as CONDITION holds,
sum EXPRESSION."
(` (let (( (, index) (, initial))
(sum 0))
(while (, condition)
(setq sum (+ sum (, expression) ))
(setq (, index) (1+ (, index))))
sum)))
(defun calendar (&optional arg)
"Display a three-month calendar in another window.
The three months appear side by side, with the current month in the middle
surrounded by the previous and next months. The cursor is put on today's date.
This function is suitable for execution in a .emacs file; appropriate setting
of the variable `view-diary-entries-initially' will cause the diary entries for
the current date to be displayed in another window. The value of the variable
`number-of-diary-entries' controls the number of days of diary entries
displayed upon initial display of the calendar.
An optional prefix argument ARG causes the calendar displayed to be ARG
months in the future if ARG is positive or in the past if ARG is negative;
in this case the cursor goes on the first day of the month.
Once in the calendar window, future or past months can be moved into view.
Arbitrary months can be displayed, or the calendar can be scrolled forward
or backward.
The cursor can be moved forward or backward by one day, one week, one month,
or one year. All of these commands take prefix arguments which, when negative,
cause movement in the opposite direction. For convenience, the digit keys
and the minus sign are automatically prefixes. The window is replotted as
necessary to display the desired date.
Diary entries can be marked on the calendar or displayed in another window.
Use M-x describe-mode for details of the key bindings in the calendar window.
The Gregorian calendar is assumed.
After preparing the calendar window initially, the hooks given by the variable
`initial-calendar-window-hook' are run.
The hooks given by the variable `today-visible-calendar-hook' are run
everytime the calendar window gets shifted, if the current date is visible
in the window. If it is not visible, the hooks given by the variable
`today-invisible-calendar-hook' are run. Thus, for example, setting
`today-visible-calendar-hook' to 'calendar-star-date will cause today's date
to be replaced by asterisks to highlight it whenever it is in the window."
(interactive "P")
(setq arg (if arg (prefix-numeric-value arg) 0))
(set-buffer (get-buffer-create calendar-buffer))
(calendar-mode)
(setq calendar-window-configuration (current-window-configuration))
(let ((pop-up-windows t)
(split-height-threshold 1000))
(pop-to-buffer calendar-buffer)
(regenerate-calendar-window arg)
(let ((date (list current-month current-day current-year)))
(if (and view-diary-entries-initially (calendar-date-is-visible-p date))
(view-diary-entries
(if (vectorp number-of-diary-entries)
(aref number-of-diary-entries (calendar-day-of-week date))
number-of-diary-entries))))
(let* ((diary-buffer (get-file-buffer diary-file))
(diary-window (if diary-buffer (get-buffer-window diary-buffer)))
(split-height-threshold (if diary-window 2 1000)))
(if view-calendar-holidays-initially
(list-calendar-holidays))))
(run-hooks 'initial-calendar-window-hook))
(autoload 'view-diary-entries "diary"
"Prepare and display a buffer with diary entries.
Searches the file diary-file for entries that match ARG days starting with
the date indicated by the cursor position in the displayed three-month
calendar."
t)
(autoload 'show-all-diary-entries "diary"
"Show all of the diary entries in the diary-file.
This function gets rid of the selective display of the diary-file so that
all entries, not just some, are visible. If there is no diary buffer, one
is created."
t)
(autoload 'mark-diary-entries "diary"
"Mark days in the calendar window that have diary entries.
Each entry in diary-file visible in the calendar window is marked."
t)
(autoload 'list-calendar-holidays "holidays"
"Create a buffer containing the holidays for the current calendar window.
The holidays are those in the list `calendar-notable-days'. Returns t if any
holidays are found, nil if not."
t)
(autoload 'mark-calendar-holidays "holidays"
"Mark notable days in the calendar window."
t)
(autoload 'calendar-cursor-holidays "holidays"
"Find holidays for the date specified by the cursor in the calendar window."
t)
(defun regenerate-calendar-window (&optional arg)
"Generate the calendar window, offset from the current date by ARG months."
(if (not arg) (setq arg 0))
(let* ((buffer-read-only nil)
(date (calendar-current-date))
(month (extract-calendar-month date))
(day (extract-calendar-day date))
(year (extract-calendar-year date))
(day-in-week (calendar-day-of-week date)))
(setq mode-line-format
(format
"C-X < Calendar ? help/o other/c current %17s C-X >"
(calendar-date-string date t)))
(setq current-month month)
(setq current-day day)
(setq current-year year)
(increment-calendar-month month year arg)
(generate-calendar month year))
(if mark-holidays-in-calendar
(mark-calendar-holidays))
(unwind-protect
(if mark-diary-entries-in-calendar
(mark-diary-entries))
(set-buffer-modified-p nil)
(or (one-window-p t)
(/= (screen-width) (window-width))
(shrink-window (- (window-height) 9)))
(if (and (<= arg 1) (>= arg -1))
(progn;; When the current date is on the screen.
(calendar-cursor-to-visible-date
(list current-month current-day current-year))
(run-hooks 'today-visible-calendar-hook))
;; When the current date is not on the screen.
(calendar-cursor-to-visible-date
(list displayed-month 1 displayed-year))
(run-hooks 'today-invisible-calendar-hook))))
(defun generate-calendar (month year)
"Generate a three-month Gregorian calendar centered around MONTH, YEAR."
(if (< (+ month (* 12 (1- year))) 2)
(error "Months before February, 1 AD are not available."))
(setq displayed-month month)
(setq displayed-year year)
(erase-buffer)
(increment-calendar-month month year -1)
(calendar-for-loop i from 0 to 2 do
(generate-calendar-month month year (+ 5 (* 25 i)))
(increment-calendar-month month year 1)))
(defun generate-calendar-month (month year indent)
"Produce a calendar for MONTH, YEAR on the Gregorian calendar.
The calendar is inserted in the buffer starting at the line on which point
is currently located, but indented INDENT spaces. The indentation is done
from the first character on the line and does not disturb the first INDENT
characters on the line."
(let* ((first-day-of-month (calendar-day-of-week (list month 1 year)))
(first-saturday (- 7 first-day-of-month))
(last (calendar-last-day-of-month month year)))
(goto-char (point-min))
(calendar-insert-indented
(format " %s %d" (calendar-month-name month) year) indent t)
(calendar-insert-indented " S M Tu W Th F S" indent t)
(calendar-insert-indented "" indent);; Move to appropriate spot on line
;; Add blank days before the first of the month
(calendar-for-loop i from 1 to first-day-of-month do
(insert " "))
;; Put in the days of the month
(calendar-for-loop i from 1 to last do
(insert (format "%2d " i))
(and (= (mod i 7) (mod first-saturday 7))
(/= i last)
(calendar-insert-indented "" 0 t) ;; Force onto following line
(calendar-insert-indented "" indent)))));; Go to proper spot
(defun calendar-insert-indented (string indent &optional newline)
"Insert STRING at column INDENT.
If the optional parameter NEWLINE is t, leave point at start of next line,
inserting a newline if there was no next line; otherwise, leave point after
the inserted text. Value is always t."
;; Try to move to that column.
(move-to-column indent)
;; If line is too short, indent out to that column.
(if (< (current-column) indent)
(indent-to indent))
(insert string)
;; Advance to next line, if requested.
(if newline
(progn
(end-of-line)
(if (eobp)
(newline)
(forward-line 1))))
t)
(defvar calendar-mode-map nil)
(if calendar-mode-map
nil
(setq calendar-mode-map (make-sparse-keymap))
(calendar-for-loop i from 0 to 9 do
(define-key calendar-mode-map (int-to-string i) 'digit-argument))
(define-key calendar-mode-map "-" 'negative-argument)
(define-key calendar-mode-map "\C-x>" 'shift-calendar-right)
(define-key calendar-mode-map "\ev" 'shift-calendar-right-three-months)
(define-key calendar-mode-map "\C-x<" 'shift-calendar-left)
(define-key calendar-mode-map "\C-v" 'shift-calendar-left-three-months)
(define-key calendar-mode-map "\C-b" 'calendar-backward-day)
(define-key calendar-mode-map "\C-p" 'calendar-backward-week)
(define-key calendar-mode-map "\e[" 'calendar-backward-month)
(define-key calendar-mode-map "\C-x[" 'calendar-backward-year)
(define-key calendar-mode-map "\C-f" 'calendar-forward-day)
(define-key calendar-mode-map "\C-n" 'calendar-forward-week)
(define-key calendar-mode-map "\e]" 'calendar-forward-month)
(define-key calendar-mode-map "\C-x]" 'calendar-forward-year)
(define-key calendar-mode-map "\C-a" 'calendar-beginning-of-week)
(define-key calendar-mode-map "\C-e" 'calendar-end-of-week)
(define-key calendar-mode-map "\ea" 'calendar-beginning-of-month)
(define-key calendar-mode-map "\ee" 'calendar-end-of-month)
(define-key calendar-mode-map "\e<" 'calendar-beginning-of-year)
(define-key calendar-mode-map "\e>" 'calendar-end-of-year)
(define-key calendar-mode-map "c" 'calendar-current-month)
(define-key calendar-mode-map "o" 'calendar-other-month)
(define-key calendar-mode-map "q" 'exit-calendar)
(define-key calendar-mode-map "a" 'list-calendar-holidays)
(define-key calendar-mode-map "h" 'calendar-cursor-holidays)
(define-key calendar-mode-map "x" 'mark-calendar-holidays)
(define-key calendar-mode-map "u" 'calendar-unmark)
(define-key calendar-mode-map "m" 'mark-diary-entries)
(define-key calendar-mode-map "d" 'view-diary-entries)
(define-key calendar-mode-map "s" 'show-all-diary-entries)
(define-key calendar-mode-map "D" 'cursor-to-calendar-day-of-year)
(define-key calendar-mode-map "C" 'cursor-to-iso-calendar-date)
(define-key calendar-mode-map "J" 'cursor-to-julian-calendar-date)
(define-key calendar-mode-map "H" 'cursor-to-hebrew-calendar-date)
(define-key calendar-mode-map "I" 'cursor-to-islamic-calendar-date)
(define-key calendar-mode-map "?" 'describe-mode))
;; Calendar mode is suitable only for specially formatted data.
(put 'calendar-mode 'mode-class 'special)
(defun calendar-mode ()
"A major mode for the sliding calendar window and diary.
The commands for cursor movement are:\\<calendar-mode-map>
\\[calendar-forward-day] one day forward \\[calendar-backward-day] one day backward
\\[calendar-forward-week] one week forward \\[calendar-backward-week] one week backward
\\[calendar-forward-month] one month forward \\[calendar-backward-month] one month backward
\\[calendar-forward-year] one year forward \\[calendar-backward-year] one year backward
\\[calendar-beginning-of-week] beginning of week \\[calendar-end-of-week] end of week
\\[calendar-beginning-of-month] beginning of month \\[calendar-end-of-month] end of month
\\[calendar-beginning-of-year] beginning of year \\[calendar-end-of-year] end of year
The commands for calendar movement are:
\\[shift-calendar-right] shift one month right \\[shift-calendar-left] shift one month left
\\[shift-calendar-right-three-months] shift 3 months right \\[shift-calendar-left-three-months] shift 3 months left
\\[calendar-current-month] display current date \\[calendar-other-month] display another date
Except for the last two, all of the above commands take prefix arguments
that multiply their affect. For convenience, the digit keys and the minus
sign are bound to digit-argument, so they need not be prefixed with ESC.
The following commands deal with holidays and other notable days:
\\[calendar-cursor-holidays] give holidays for the date specified by the cursor
\\[mark-calendar-holidays] mark notable days
\\[calendar-unmark] unmark dates
\\[list-calendar-holidays] display notable days
The command M-x holidays causes the notable dates for the current month, and
the preceding and succeeding months, to be displayed, independently of the
calendar.
The following commands control the diary:
\\[mark-diary-entries] mark diary entries \\[calendar-unmark] unmark dates
\\[view-diary-entries] display diary entries \\[show-all-diary-entries] show all diary entries
\\[print-diary-entries] print diary entries
Displaying the diary entries causes the dairy entries from the diary-file
(for the date indicated by the cursor in the calendar window) to be
displayed in another window. This function takes an integer argument that
specifies the number of days of calendar entries to be displayed, starting
with the date indicated by the cursor.
The command \\[print-diary-entries] prints the diary buffer (as it appears)
on the line printer.
The command M-x diary causes the diary entries for the current date to be
displayed, independently of the calendar. The number of days of entries is
governed by number-of-diary-entries.
The format of the entries in the diary file is described in the
documentation string for the variable diary-file.
When diary entries are in view in the window, they can be edited. It is
important to keep in mind that the buffer displayed contains the entire
diary file, but with portions of it concealed from view. This means, for
instance, that the forward-char command can put the cursor at what appears
to be the end of the line, but what is in reality the middle of some
concealed line. BE CAREFUL WHEN EDITING THE DIARY ENTRIES! (Inserting
additional lines or adding/deleting characters in the middle of a visible
line will not cause problems; watch out for end-of-line, however--it may
put you at the end of a concealed line far from where the cursor appears to
be!) BEFORE EDITING THE DIARY IT IS BEST TO DISPLAY THE ENTIRE FILE WITH
show-all-diary-entries. BE SURE TO WRITE THE FILE BEFORE EXITING FROM THE
CALENDAR.
The day number in the year and the number of days remaining in the year can be
determined by
\\[cursor-to-calendar-day-of-year] show day number and the number of days remaining in the year
Equivalent dates on the ISO commercial, Julian, Hebrew, and Islamic calendars
can be determined by
\\[cursor-to-iso-calendar-date] show equivalent date on the ISO commercial calendar
\\[cursor-to-julian-calendar-date] show equivalent date on the Julian calendar
\\[cursor-to-hebrew-calendar-date] show equivalent date on the Hebrew calendar
\\[cursor-to-islamic-calendar-date] show equivalent date on the Islamic calendar
To exit from the calendar use
\\[exit-calendar] exit from calendar
The variable `view-diary-entries-initially', whose default is nil, can be
set to to t cause diary entries for the current date will be displayed in
another window when the calendar is first displayed, if the current date is
visible. The variable `number-of-diary-entries' controls number of days of
diary entries that will be displayed initially or with the command M-x
diary. For example, if the default value 1 is used, then only the current
day's diary entries will be displayed. If the value 2 is used, both the
current day's and the next day's entries will be displayed. The value can
also be a vector: If the value is [0 2 2 2 2 4 1] then no diary entries
will be displayed on Sunday, the current date's and the next day's diary
entries will be displayed Monday through Thursday, Friday through Monday's
entries will be displayed on Friday, while on Saturday only that day's
entries will be displayed.
The variable `view-calendar-holidays-initially' can be set to t to cause
the holidays for the current three month period will be displayed on entry
to the calendar. The holidays are displayed in another window.
The variable `mark-diary-entries-in-calendar' can be set to t to cause any
dates visible with calendar entries to be marked with the symbol specifed
by the variable `diary-entry-marker', normally a plus sign.
The variable `initial-calendar-window-hook', whose default value is nil,
is list of functions to be called when the calendar window is first opened.
The functions invoked are called after the calendar window is opened, but
once opened is never called again. Leaving the calendar with the `q' command
and reentering it will cause these functions to be called again.
The variable `today-visible-calendar-hook', whose default value is nil,
is the list of functions called after the calendar buffer has been prepared
with the calendar when the current date is visible in the window.
This can be used, for example, to replace today's date with asterisks; a
function calendar-star-date is included for this purpose:
(setq today-visible-calendar-hook 'calendar-star-date)
It could also be used to mark the current date with `*'; a function is also
provided for this:
(setq today-visible-calendar-hook 'calendar-mark-today)
The variable `today-invisible-calendar-hook', whose default value is nil,
is the list of functions called after the calendar buffer has been prepared
with the calendar when the current date is not visible in the window.
The variable `list-diary-entries-hook' is the list of functions called
after the diary buffer is prepared. The default value simply displays the
diary file using selective-display to conceal irrelevant diary entries. An
alternative function `prepare-fancy-diary-buffer' is provided that, when
used as the `list-diary-entries-hook', causes a noneditable buffer to be
prepared with a neatly organized day-by-day listing of relevant diary
entries, together with any known holidays. The inclusion of the holidays
slows this fancy display of the diary; to speed it up, set the variable
`holidays-in-diary-buffer' to nil.
The variable `print-diary-entries-hook' is the list of functions called
after a temporary buffer is prepared with the diary entries currently
visible in the diary buffer. The default value of this hook adds a heading
(composed from the diary buffer's mode line), does the printing with the
command lpr-buffer, and kills the temporary buffer. Other uses might
include, for example, rearranging the lines into order by day and time.
The Gregorian calendar is assumed."
(kill-all-local-variables)
(setq major-mode 'calendar-mode)
(setq mode-name "Calendar")
(use-local-map calendar-mode-map)
(setq buffer-read-only t)
(setq indent-tabs-mode nil)
(make-local-variable 'mode-line-format)
(make-local-variable 'calendar-window-configuration);; Windows on entry.
(make-local-variable 'current-month) ;; Current month.
(make-local-variable 'current-day) ;; Current day.
(make-local-variable 'current-year) ;; Current year.
(make-local-variable 'displayed-month);; Month in middle of window.
(make-local-variable 'displayed-year));; Year in middle of window.
(defun exit-calendar ()
"Get out of the calendar window and destroy it and related buffers."
(interactive)
(let ((diary-buffer (get-file-buffer diary-file))
(d-buffer (get-buffer fancy-diary-buffer))
(h-buffer (get-buffer holiday-buffer)))
(if (not diary-buffer)
(progn
(set-window-configuration calendar-window-configuration)
(kill-buffer calendar-buffer)
(if d-buffer (kill-buffer d-buffer))
(if h-buffer (kill-buffer h-buffer)))
(if (or (not (buffer-modified-p diary-buffer))
(yes-or-no-p "Diary modified; do you really want to exit the calendar? "))
(progn
(set-window-configuration calendar-window-configuration)
(kill-buffer calendar-buffer)
(if d-buffer (kill-buffer d-buffer))
(if h-buffer (kill-buffer h-buffer))
(set-buffer diary-buffer)
(set-buffer-modified-p nil)
(kill-buffer diary-buffer))))))
(defun calendar-current-month ()
"Reposition the calendar window so the current date is visible."
(interactive)
(let ((date (calendar-current-date)));; The date might have changed.
(if (calendar-date-is-visible-p date)
(calendar-cursor-to-visible-date date)
(regenerate-calendar-window))))
(defun calendar-forward-month (arg)
"Move the cursor forward ARG months.
Movement is backward if ARG is negative."
(interactive "p")
(calendar-cursor-to-nearest-date)
(let*
((cursor-date (or (calendar-cursor-to-date)
(error "Cursor is not on a date!")))
(month (extract-calendar-month cursor-date))
(day (extract-calendar-day cursor-date))
(year (extract-calendar-year cursor-date)))
(increment-calendar-month month year arg)
(let ((last (calendar-last-day-of-month month year)))
(if (< last day)
(setq day last)))
;; Put the new month on the screen, if needed, and go to the new date.
(let ((new-cursor-date (list month day year)))
(if (not (calendar-date-is-visible-p new-cursor-date))
(calendar-other-month month year))
(calendar-cursor-to-visible-date new-cursor-date))))
(defun calendar-forward-year (arg)
"Move the cursor forward by ARG years.
Movement is backward if ARG is negative."
(interactive "p")
(calendar-forward-month (* 12 arg)))
(defun calendar-backward-month (arg)
"Move the cursor backward by ARG months.
Movement is forward if ARG is negative."
(interactive "p")
(calendar-forward-month (- arg)))
(defun calendar-backward-year (arg)
"Move the cursor backward ARG years.
Movement is forward is ARG is negative."
(interactive "p")
(calendar-forward-month (* -12 arg)))
(defun shift-calendar-left (arg)
"Shift the displayed calendar left by ARG months.
If ARG is negative the calendar is shifted right. Maintains the relative
position of the cursor with respect to the calendar as well as possible."
(interactive "p")
(let ((old-date (calendar-cursor-to-date))
(today (calendar-current-date)))
(if (/= arg 0)
(progn
(regenerate-calendar-window
(+ arg (calendar-interval current-month current-year
displayed-month displayed-year)))
(calendar-cursor-to-visible-date
(cond
((calendar-date-is-visible-p old-date) old-date)
((calendar-date-is-visible-p today) today)
(t (list displayed-month 1 displayed-year))))))))
(defun shift-calendar-right (arg)
"Shift the displayed calendar window right by ARG months.
If ARG is negative the calendar is shifted left. Maintains the relative
position of the cursor with respect to the calendar as well as possible."
(interactive "p")
(shift-calendar-left (- arg)))
(defun shift-calendar-left-three-months (arg)
"Shift the displayed calendar window left by 3*ARG months.
If ARG is negative the calendar is shifted right. Maintains the relative
position of the cursor with respect to the calendar as well as possible."
(interactive "p")
(shift-calendar-left (* 3 arg)))
(defun shift-calendar-right-three-months (arg)
"Shift the displayed calendar window right by 3*ARG months.
If ARG is negative the calendar is shifted left. Maintains the relative
position of the cursor with respect to the calendar as well as possible."
(interactive "p")
(shift-calendar-left (* -3 arg)))
(defun calendar-current-date ()
"Returns the current date in a list (month day year).
If in the calendar buffer, also sets the current date local variables."
(let* ((date (current-time-string))
(garbage
(string-match
"^\\([A-Z][a-z]*\\) *\\([A-Z][a-z]*\\) *\\([0-9]*\\) .* \\([0-9]*\\)$"
date))
(month
(cdr (assoc
(substring date (match-beginning 2) (match-end 2))
calendar-month-abbrev-list)))
(day
(string-to-int (substring date (match-beginning 3) (match-end 3))))
(year
(string-to-int (substring date (match-beginning 4) (match-end 4)))))
(if (equal (current-buffer) (get-buffer calendar-buffer))
(progn
(setq current-month month)
(setq current-day day)
(setq current-year year)))
(list month day year)))
(defun calendar-cursor-to-date ()
"Returns a list of the month, day, and year of current cursor position.
Returns nil if the cursor is not on a specific day."
(if (and (looking-at "[*0-9]")
(< 2 (count-lines (point-min) (point))))
(save-excursion
(re-search-backward "[^0-9]")
(forward-char 1)
(let*
((day (string-to-int (buffer-substring (point) (+ 3 (point)))))
(day (if (= 0 day) current-day day));; Starred date.
(segment (/ (current-column) 25))
(month (mod (+ displayed-month segment -1) 12))
(month (if (= 0 month) 12 month))
(year
(cond
((and (= 12 month) (= segment 0)) (1- displayed-year))
((and (= 1 month) (= segment 2)) (1+ displayed-year))
(t displayed-year))))
(list month day year)))))
(defun calendar-cursor-to-nearest-date ()
"Move the cursor to the closest date.
The position of the cursor is unchanged if it is already on a date.
Returns the list (month day year) giving the cursor position."
(let ((date (calendar-cursor-to-date))
(column (current-column)))
(if date
date
(if (> 3 (count-lines (point-min) (point)))
(progn
(goto-line 3)
(move-to-column column)))
(if (not (looking-at "[0-9]"))
(if (and (not (looking-at " *$"))
(or (< column 25)
(and (> column 27)
(< column 50))
(and (> column 52)
(< column 75))))
(progn
(re-search-forward "[0-9]" nil t)
(backward-char 1))
(re-search-backward "[0-9]" nil t)))
(calendar-cursor-to-date))))
(defun calendar-forward-day (arg)
"Move the cursor forward ARG days.
Moves backward if ARG is negative."
(interactive "p")
(if (/= 0 arg)
(let*
((cursor-date (calendar-cursor-to-date))
(cursor-date (if cursor-date
cursor-date
(setq arg (if (< arg 0) (1+ arg) (1- arg)))
(calendar-cursor-to-nearest-date)))
(new-cursor-date
(calendar-gregorian-from-absolute
(+ (calendar-absolute-from-gregorian cursor-date) arg)))
(new-display-month (extract-calendar-month new-cursor-date))
(new-display-year (extract-calendar-year new-cursor-date)))
;; Put the new month on the screen, if needed, and go to the new date.
(if (not (calendar-date-is-visible-p new-cursor-date))
(calendar-other-month new-display-month new-display-year))
(calendar-cursor-to-visible-date new-cursor-date))))
(defun calendar-backward-day (arg)
"Move the cursor back ARG days.
Moves forward if ARG is negative."
(interactive "p")
(calendar-forward-day (- arg)))
(defun calendar-forward-week (arg)
"Move the cursor forward ARG weeks.
Moves backward if ARG is negative."
(interactive "p")
(calendar-forward-day (* arg 7)))
(defun calendar-backward-week (arg)
"Move the cursor back ARG weeks.
Moves forward if ARG is negative."
(interactive "p")
(calendar-forward-day (* arg -7)))
(defun calendar-beginning-of-week (arg)
"Move the cursor back ARG Sundays."
(interactive "p")
(calendar-cursor-to-nearest-date)
(let ((day (calendar-day-of-week (calendar-cursor-to-date))))
(calendar-backward-day
(if (= day 0) (* 7 arg) (+ day (* 7 (1- arg)))))))
(defun calendar-end-of-week (arg)
"Move the cursor forward ARG Saturdays."
(interactive "p")
(calendar-cursor-to-nearest-date)
(let ((day (calendar-day-of-week (calendar-cursor-to-date))))
(calendar-forward-day
(if (= day 6) (* 7 arg) (+ (- 6 day) (* 7 (1- arg)))))))
(defun calendar-beginning-of-month (arg)
"Move the cursor backward ARG month beginnings."
(interactive "p")
(calendar-cursor-to-nearest-date)
(let* ((date (calendar-cursor-to-date))
(month (extract-calendar-month date))
(day (extract-calendar-day date))
(year (extract-calendar-year date)))
(if (= day 1)
(calendar-backward-month arg)
(calendar-cursor-to-visible-date (list month 1 year))
(calendar-backward-month (1- arg)))))
(defun calendar-end-of-month (arg)
"Move the cursor forward ARG month ends."
(interactive "p")
(calendar-cursor-to-nearest-date)
(let* ((date (calendar-cursor-to-date))
(month (extract-calendar-month date))
(day (extract-calendar-day date))
(year (extract-calendar-year date))
(last-day (calendar-last-day-of-month month year)))
(if (/= day last-day)
(progn
(calendar-cursor-to-visible-date (list month last-day year))
(setq arg (1- arg))))
(increment-calendar-month month year arg)
(let ((last-day (list
month
(calendar-last-day-of-month month year)
year)))
(if (not (calendar-date-is-visible-p last-day))
(calendar-other-month month year)
(calendar-cursor-to-visible-date last-day)))))
(defun calendar-beginning-of-year (arg)
"Move the cursor backward ARG year beginnings."
(interactive "p")
(calendar-cursor-to-nearest-date)
(let* ((date (calendar-cursor-to-date))
(month (extract-calendar-month date))
(day (extract-calendar-day date))
(year (extract-calendar-year date))
(jan-first (list 1 1 year)))
(if (and (= day 1) (= 1 month))
(calendar-backward-month (* 12 arg))
(if (and (= arg 1)
(calendar-date-is-visible-p jan-first))
(calendar-cursor-to-visible-date jan-first)
(calendar-other-month 1 (- year (1- arg)))))))
(defun calendar-end-of-year (arg)
"Move the cursor forward ARG year beginnings."
(interactive "p")
(calendar-cursor-to-nearest-date)
(let* ((date (calendar-cursor-to-date))
(month (extract-calendar-month date))
(day (extract-calendar-day date))
(year (extract-calendar-year date))
(year (extract-calendar-year date))
(dec-31 (list 12 31 year)))
(if (and (= day 31) (= 12 month))
(calendar-forward-month (* 12 arg))
(if (and (= arg 1)
(calendar-date-is-visible-p dec-31))
(calendar-cursor-to-visible-date dec-31)
(calendar-other-month 12 (- year (1- arg)))
(calendar-cursor-to-visible-date (list 12 31 displayed-year))))))
(defun extract-calendar-month (date)
"Extract the month part of DATE which has the form (month day year)."
(car date))
(defun extract-calendar-day (date)
"Extract the day part of DATE which has the form (month day year)."
(car (cdr date)))
(defun extract-calendar-year (date)
"Extract the year part of DATE which has the form (month day year)."
(car (cdr (cdr date))))
(defun calendar-gregorian-from-absolute (date)
"Compute the list (month day year) corresponding to the absolute DATE.
The absolute date is the number of days elapsed since the (imaginary)
Gregorian date Sunday, December 31, 1 BC."
(let* ((approx (/ date 366));; Approximation from below.
(year ;; Search forward from the approximation.
(+ approx
(calendar-sum y approx
(>= date (calendar-absolute-from-gregorian (list 1 1 (1+ y))))
1)))
(month ;; Search forward from January.
(1+ (calendar-sum m 1
(> date
(calendar-absolute-from-gregorian
(list m (calendar-last-day-of-month m year) year)))
1)))
(day ;; Calculate the day by subtraction.
(- date
(1- (calendar-absolute-from-gregorian (list month 1 year))))))
(list month day year)))
(defun calendar-cursor-to-visible-date (date)
"Move the cursor to DATE that is on the screen."
(let ((month (extract-calendar-month date))
(day (extract-calendar-day date))
(year (extract-calendar-year date)))
(goto-line (+ 3
(/ (+ day -1
(calendar-day-of-week (list month 1 year)))
7)))
(move-to-column (+ 6
(* 25
(1+ (calendar-interval
displayed-month displayed-year month year)))
(* 3 (calendar-day-of-week date))))))
(defun calendar-other-month (month year)
"Display a three-month calendar centered around MONTH and YEAR."
(interactive "nMonth (1-12): \nnYear (>0): ")
(if (or (< 12 month) (> 1 month) (> 1 year))
(error "Unacceptable month/year!"))
(if (and (= month displayed-month)
(= year displayed-year))
nil
(let ((old-date (calendar-cursor-to-date))
(today (calendar-current-date)))
(regenerate-calendar-window
(calendar-interval current-month current-year month year))
(calendar-cursor-to-visible-date
(cond
((calendar-date-is-visible-p old-date) old-date)
((calendar-date-is-visible-p today) today)
(t (list month 1 year)))))))
(defun calendar-interval (mon1 yr1 mon2 yr2)
"The number of months difference between the two specified months."
(+ (* 12 (- yr2 yr1))
(- mon2 mon1)))
(defun calendar-leap-year-p (year)
"Returns t if YEAR is a Gregorian leap year."
(or
(and (= (mod year 4) 0)
(/= (mod year 100) 0))
(= (mod year 400) 0)))
(defun calendar-day-number (date)
"Return the day number within the year of the date DATE.
For example, (calendar-day-number '(1 1 1987)) returns the value 1,
while (calendar-day-number '(12 31 1980)) returns 366."
;;
;; An explanation of the calculation can be found in PascAlgorithms by
;; Edward and Ruth Reingold, Scott-Foresman/Little, Brown, 1988.
;;
(let* ((month (extract-calendar-month date))
(day (extract-calendar-day date))
(year (extract-calendar-year date))
(day-of-year (+ day (* 31 (1- month)))))
(if (> month 2)
(progn
(setq day-of-year (- day-of-year (/ (+ 23 (* 4 month)) 10)))
(if (calendar-leap-year-p year)
(setq day-of-year (1+ day-of-year)))))
day-of-year))
(defun calendar-day-name (date)
"Returns a string with the name of the day of the week of DATE."
(aref calendar-day-name-array (calendar-day-of-week date)))
(defconst calendar-day-name-array
["Sunday" "Monday" "Tuesday" "Wednesday" "Thursday" "Friday" "Saturday"])
(defun calendar-last-day-of-month (month year)
"The last day in MONTH during YEAR."
(if (and (calendar-leap-year-p year) (= month 2))
29
(aref [31 28 31 30 31 30 31 31 30 31 30 31] (1- month))))
(defconst calendar-month-name-array
["January" "February" "March" "April" "May" "June"
"July" "August" "September" "October" "November" "December"])
(defun calendar-month-name (month)
"The name of MONTH."
(aref calendar-month-name-array (1- month)))
(defconst calendar-month-abbrev-list
'(("Jan" . 1) ("Feb" . 2) ("Mar" . 3) ("Apr" . 4)
("May" . 5) ("Jun" . 6) ("Jul" . 7) ("Aug" . 8)
("Sep" . 9) ("Oct" . 10) ("Nov" . 11) ("Dec" . 12)))
(defconst calendar-day-abbrev-list
'(("Sun" . 0) ("Mon" . 1) ("Tue" . 2) ("Wed" . 3)
("Thu" . 4) ("Fri" . 5) ("Sat" . 6)))
(defun calendar-day-of-week (date)
"Returns the day-of-the-week index of DATE, 0 for Sunday, 1 for Monday, etc."
(mod (calendar-absolute-from-gregorian date) 7))
(defun calendar-absolute-from-gregorian (date)
"The number of days elapsed between the Gregorian date 12/31/1 BC and DATE.
The Gregorian date Sunday, December 31, 1 BC is imaginary."
(let ((month (extract-calendar-month date))
(day (extract-calendar-day date))
(year (extract-calendar-year date)))
(-
(+ (calendar-day-number date)
(* 365 (1- year))
(/ (1- year) 4))
(let ((correction (* (/ (1- year) 100) 3)))
(if (= (mod correction 4) 0)
(/ correction 4)
(1+ (/ correction 4)))))))
(defun calendar-unmark ()
"Delete the diary and holiday marks from the calendar."
(interactive)
(save-excursion
(goto-line 3)
(beginning-of-line)
(let ((buffer-read-only nil)
(start (point))
(star-date (search-forward "**" nil t))
(star-point (point)))
(if star-date
(progn ;; Don't delete today as left by calendar-star-date
(subst-char-in-region start (- star-point 2)
(string-to-char diary-entry-marker) ? t)
(subst-char-in-region start (- star-point 2)
(string-to-char calendar-holiday-marker) ? t)
(subst-char-in-region star-point (point-max)
(string-to-char diary-entry-marker) ? t)
(subst-char-in-region star-point (point-max)
(string-to-char calendar-holiday-marker) ? t))
(subst-char-in-region start (point-max)
(string-to-char diary-entry-marker) ? t)
(subst-char-in-region start (point-max)
(string-to-char calendar-holiday-marker) ? t))
(set-buffer-modified-p nil))))
(defun calendar-date-is-visible-p (date)
"Returns t if DATE is legal and is visible in the calendar window."
(save-excursion
(if (bufferp calendar-buffer) (set-buffer calendar-buffer))
(let ((gap (calendar-interval
displayed-month displayed-year
(extract-calendar-month date) (extract-calendar-year date))))
(and (calendar-date-is-legal-p date) (> 2 gap) (< -2 gap)))))
(defun calendar-date-is-legal-p (date)
"Returns t if DATE is a legal date."
(let ((month (extract-calendar-month date))
(day (extract-calendar-day date))
(year (extract-calendar-year date)))
(and (<= 1 month) (<= month 12)
(<= 1 day) (<= day (calendar-last-day-of-month month year))
(<= 1 year))))
(defun calendar-date-equal (date1 date2)
"Returns t if the DATE1 and DATE2 are the same."
(and
(= (extract-calendar-month date1) (extract-calendar-month date2))
(= (extract-calendar-day date1) (extract-calendar-day date2))
(= (extract-calendar-year date1) (extract-calendar-year date2))))
(defun mark-visible-calendar-date (date &optional mark)
"Leave mark DATE with MARK. MARK defaults to diary-entry-marker."
(if (calendar-date-is-legal-p date)
(save-excursion
(set-buffer calendar-buffer)
(calendar-cursor-to-visible-date date)
(forward-char 1)
(let ((buffer-read-only nil))
(delete-char 1)
(insert (if mark mark diary-entry-marker))
(forward-char -2))
(set-buffer-modified-p nil))))
(defun calendar-star-date ()
"Replace the date under the cursor in the calendar window with asterisks.
This function can be used with the today-visible-calendar-hook run after the
calendar window has been prepared."
(let ((buffer-read-only nil))
(forward-char 1)
(delete-char -2)
(insert "**")
(backward-char 1)
(set-buffer-modified-p nil)))
(defun calendar-mark-today ()
"Mark the date under the cursor in the calendar window with an asterisk.
This function can be used with the today-visible-calendar-hook run after the
calendar window has been prepared."
(let ((buffer-read-only nil))
(forward-char 1)
(delete-char 1)
(insert "*")
(backward-char 2)
(set-buffer-modified-p nil)))
(defun calendar-date-compare (date1 date2)
"Returns t if DATE1 is before DATE2, nil otherwise.
The actual dates are in the car of DATE1 and DATE2."
(< (calendar-absolute-from-gregorian (car date1))
(calendar-absolute-from-gregorian (car date2))))
(defun calendar-date-string (date &optional abbreviate)
"A string form of DATE, driven by the variable `calendar-date-display-form'.
An optional parameter ABBREVIATE, when t, causes the month and day names to be
abbreviated to three characters."
(let* ((dayname
(if abbreviate
(substring (calendar-day-name date) 0 3)
(calendar-day-name date)))
(month (extract-calendar-month date))
(monthname
(if abbreviate
(substring
(calendar-month-name month) 0 3)
(calendar-month-name month)))
(day (int-to-string (extract-calendar-day date)))
(month (int-to-string month))
(year (int-to-string (extract-calendar-year date))))
(mapconcat
'(lambda (x) (if (stringp x) x (eval x)))
calendar-date-display-form "")))
(defun calendar-dayname-on-or-before (dayname date)
"Returns the absolute date of the DAYNAME on or before DATE.
DAYNAME=0 means Sunday, DAYNAME=1 means Monday, and so on.
Note: Applying this function to d+6 gives us the DAYNAME on or after an
absolute day d. Similarly, applying it to d+3 gives the DAYNAME nearest to
absolute date d, applying it to d-1 gives the DAYNAME previous to absolute
date d, and applying it to d+7 gives the DAYNAME following absolute date d."
(- date (mod (- date dayname) 7)))
(defun calendar-nth-named-day (n dayname month year)
"Returns the date of the Nth DAYNAME in MONTH, YEAR.
A DAYNAME of 0 means Sunday, 1 means Monday, and so on. If N<0, the
date returned is the Nth DAYNAME from the end of MONTH, YEAR (that is, -1 is
the last DAYNAME, -2 is the penultimate DAYNAME, and so on."
(calendar-gregorian-from-absolute
(if (> n 0)
(+ (calendar-dayname-on-or-before
dayname (calendar-absolute-from-gregorian (list month 7 year)))
(* 7 (1- n)))
(+ (calendar-dayname-on-or-before
dayname
(calendar-absolute-from-gregorian
(list month (calendar-last-day-of-month month year) year)))
(* 7 (1+ n))))))
(defun cursor-to-calendar-day-of-year ()
"Show the day number in the year and the number of days remaining in the
year for the date under the cursor."
(interactive)
(let* ((date (or (calendar-cursor-to-date)
(error "Cursor is not on a date!")))
(year (extract-calendar-year date))
(day (calendar-day-number date)))
(message "Day %d of %d; %d days remaining in the year."
day year (- (calendar-day-number (list 12 31 year)) day))))
(defun calendar-absolute-from-iso (date)
"The number of days elapsed between the Gregorian date 12/31/1 BC and
DATE. The `ISO year' corresponds approximately to the Gregorian year, but
weeks start on Monday and end on Sunday. The first week of the ISO year is
the first such week in which at least 4 days are in a year. The ISO
commercial DATE has the form (week day year) in which week is in the range
1..52 and day is in the range 0..6 (1 = Monday, 2 = Tuesday, ..., 0 =
Sunday). The The Gregorian date Sunday, December 31, 1 BC is imaginary."
(let* ((week (extract-calendar-month date))
(day (extract-calendar-day date))
(year (extract-calendar-year date)))
(+ (calendar-dayname-on-or-before
1 (+ 3 (calendar-absolute-from-gregorian (list 1 1 year))))
(* 7 (1- week))
(if (= day 0) 6 (1- day)))))
(defun calendar-iso-from-absolute (date)
"Compute the `ISO commercial date' corresponding to the absolute DATE.
The ISO year corresponds approximately to the Gregorian year, but weeks
start on Monday and end on Sunday. The first week of the ISO year is the
first such week in which at least 4 days are in a year. The ISO commercial
date has the form (week day year) in which week is in the range 1..52 and
day is in the range 0..6 (1 = Monday, 2 = Tuesday, ..., 0 = Sunday). The
absolute date is the number of days elapsed since the (imaginary) Gregorian
date Sunday, December 31, 1 BC."
(let* ((approx (extract-calendar-year
(calendar-gregorian-from-absolute (- date 3))))
(year (+ approx
(calendar-sum y approx
(>= date (calendar-absolute-from-iso (list 1 1 (1+ y))))
1))))
(list
(1+ (/ (- date (calendar-absolute-from-iso (list 1 1 year))) 7))
(mod date 7)
year)))
(defun cursor-to-iso-calendar-date ()
"Show the equivalent date on the `ISO commercial calendar' for the date
under the cursor."
(interactive)
(let* ((greg-date
(or (calendar-cursor-to-date)
(error "Cursor is not on a date!")))
(iso-date (calendar-iso-from-absolute
(calendar-absolute-from-gregorian greg-date))))
(message "%s of ISO week %d of %d."
(calendar-day-name greg-date)
(extract-calendar-month iso-date)
(extract-calendar-year iso-date))))
(defun calendar-julian-from-absolute (date)
"Compute the Julian (month day year) corresponding to the absolute DATE.
The absolute date is the number of days elapsed since the (imaginary)
Gregorian date Sunday, December 31, 1 BC."
(let ((month 1)
(day 0)
(year (/ date 366)))
;; Calculate month, day, and year of DATE.
(while (<= (calendar-absolute-from-julian (list 1 1 (1+ year))) date)
(setq year (1+ year)))
(while (< (calendar-absolute-from-julian
(list month
(if (and (= month 2) (= (mod year 4) 0))
29
(aref [31 28 31 30 31 30 31 31 30 31 30 31]
(1- month)))
year))
date)
(setq month (1+ month)))
(setq day
(- (1+ date)
(calendar-absolute-from-julian (list month 1 year))))
(list month day year)))
(defun calendar-absolute-from-julian (date)
"The number of days elapsed between the Gregorian date 12/31/1 BC and DATE.
The Gregorian date Sunday, December 31, 1 BC is imaginary."
(let ((month (extract-calendar-month date))
(day (extract-calendar-day date))
(year (extract-calendar-year date)))
(+ (calendar-day-number date)
(if (and (= (mod year 100) 0)
(/= (mod year 400) 0)
(> month 2))
1 0);; Correct for Julian but not Gregorian leap year.
(* 365 (1- year))
(/ (1- year) 4)
-2)))
(defun cursor-to-julian-calendar-date ()
"Show the Julian calendar equivalent of the date under the cursor."
(interactive)
(let* ((julian-date (calendar-julian-from-absolute
(calendar-absolute-from-gregorian
(or (calendar-cursor-to-date)
(error "Cursor is not on a date!")))))
(month (extract-calendar-month julian-date))
(day (extract-calendar-day julian-date))
(year (extract-calendar-year julian-date)))
(message "Julian date: %s %d, %d"
(calendar-month-name month)
day year)))
(defun islamic-calendar-leap-year-p (year)
"Returns t if YEAR is a leap year on the Islamic calendar."
(memq (mod year 30)
(list 2 5 7 10 13 16 18 21 24 26 29)))
(defun islamic-calendar-last-day-of-month (month year)
"The last day in MONTH during YEAR on the Islamic calendar."
(cond
((memq month (list 1 3 5 7 9 11)) 30)
((memq month (list 2 4 6 8 10)) 29)
(t (if (islamic-calendar-leap-year-p year) 30 29))))
(defun islamic-calendar-day-number (date)
"Return the day number within the year of the Islamic date DATE."
(let* ((month (extract-calendar-month date))
(day (extract-calendar-day date)))
(+ (* 30 (/ month 2))
(* 29 (/ (1- month) 2))
day)))
(defun calendar-absolute-from-islamic (date)
"Absolute date of Islamic DATE.
The absolute date is the number of days elapsed since the (imaginary)
Gregorian date Sunday, December 31, 1 BC."
(let* ((month (extract-calendar-month date))
(day (extract-calendar-day date))
(year (extract-calendar-year date))
(y (mod year 30))
(leap-years-in-cycle
(cond
((< y 3) 0) ((< y 6) 1) ((< y 8) 2) ((< y 11) 3) ((< y 14) 4)
((< y 17) 5) ((< y 19) 6) ((< y 22) 7) ((< y 25) 8) ((< y 27) 9)
(t 10))))
(+ (islamic-calendar-day-number date);; days so far this year
(* (1- year) 354) ;; days in all non-leap years
(* 11 (/ year 30)) ;; leap days in complete cycles
leap-years-in-cycle ;; leap days this cycle
227014))) ;; days before start of calendar
(defun calendar-islamic-from-absolute (date)
"Compute the Islamic date (month day year) corresponding to absolute DATE.
The absolute date is the number of days elapsed since the (imaginary)
Gregorian date Sunday, December 31, 1 BC."
(if (< date 227015)
(list 0 0 0);; pre-Islamic date
(let* ((month 1)
(day 1)
(year (/ (- date 227014) 355)))
(while (>= date (calendar-absolute-from-islamic (list 1 1 (1+ year))))
(setq year (1+ year)))
(while (> date
(calendar-absolute-from-islamic
(list month
(islamic-calendar-last-day-of-month month year)
year)))
(setq month (1+ month)))
(setq day
(1+ (- date (calendar-absolute-from-islamic (list month 1 year)))))
(list month day year))))
(defun cursor-to-islamic-calendar-date ()
"Show the Islamic calendar equivalent of the date under the cursor."
(interactive)
(let* ((islamic-date (calendar-islamic-from-absolute
(calendar-absolute-from-gregorian
(or (calendar-cursor-to-date)
(error "Cursor is not on a date!")))))
(month (extract-calendar-month islamic-date))
(day (extract-calendar-day islamic-date))
(year (extract-calendar-year islamic-date)))
(if (< year 1)
(message "Date is pre-Islamic")
(message "Islamic date: %s %d, %d"
(aref ["Muharram" "Safar" "Rabi I" "Rabi II" "Jumada I"
"Jumada II" "Rajab" "Sha'ban" "Ramadan" "Shawwal"
"Dhu al-Qada" "Dhu al-Hijjah"]
(1- month))
day year))))
(defun cursor-to-hebrew-calendar-date ()
"Show the Hebrew calendar equivalent of the date under the cursor."
(interactive)
(let* ((hebrew-date (calendar-hebrew-from-absolute
(calendar-absolute-from-gregorian
(or (calendar-cursor-to-date)
(error "Cursor is not on a date!")))))
(m (extract-calendar-month hebrew-date))
(d (extract-calendar-day hebrew-date))
(y (extract-calendar-year hebrew-date)))
(message "Hebrew date: %s %d, %d"
(if (and (hebrew-calendar-leap-year-p y) (= m 12))
"Adar I"
(aref ["Nisan" "Iyar" "Sivan" "Tammuz" "Av" "Elul" "Tishri"
"Heshvan" "Kislev" "Teveth" "Shevat" "Adar" "Adar II"]
(1- m)))
d y)))
(defun calendar-hebrew-from-absolute (date)
"Compute the Hebrew date (month day year) corresponding to absolute DATE.
The absolute date is the number of days elapsed since the (imaginary)
Gregorian date Sunday, December 31, 1 BC."
(let* ((greg-date (calendar-gregorian-from-absolute date))
(month (aref [9 10 11 12 1 2 3 4 7 7 7 8]
(1- (extract-calendar-month greg-date))))
(day)
(year (+ 3760 (extract-calendar-year greg-date))))
(while (>= date (calendar-absolute-from-hebrew (list 7 1 (1+ year))))
(setq year (1+ year)))
(let ((length (hebrew-calendar-last-month-of-year year)))
(while (> date
(calendar-absolute-from-hebrew
(list month
(hebrew-calendar-last-day-of-month month year)
year)))
(setq month (1+ (mod month length)))))
(setq day (1+
(- date (calendar-absolute-from-hebrew (list month 1 year)))))
(list month day year)))
(defun hebrew-calendar-leap-year-p (year)
"t if YEAR is a Hebrew calendar leap year."
(< (mod (1+ (* 7 year)) 19) 7))
(defun hebrew-calendar-last-month-of-year (year)
"The last month of the Hebrew calendar YEAR."
(if (hebrew-calendar-leap-year-p year)
13
12))
(defun hebrew-calendar-last-day-of-month (month year)
"The last day of MONTH in YEAR."
(if (or (memq month (list 2 4 6 10 13))
(and (= month 12) (not (hebrew-calendar-leap-year-p year)))
(and (= month 8) (not (hebrew-calendar-long-heshvan-p year)))
(and (= month 9) (hebrew-calendar-short-kislev-p year)))
29
30))
(defun hebrew-calendar-elapsed-days (year)
"Number of days elapsed from the Sunday prior to the start of the Hebrew
calendar to the mean conjunction of Tishri of Hebrew YEAR."
(let* ((months-elapsed
(+ (* 235 (/ (1- year) 19));; Months in complete cycles so far.
(* 12 (mod (1- year) 19)) ;; Regular months in this cycle
(/ (1+ (* 7 (mod (1- year) 19))) 19)));; Leap months this cycle
(parts-elapsed (+ 204 (* 793 (mod months-elapsed 1080))))
(hours-elapsed (+ 5
(* 12 months-elapsed)
(* 793 (/ months-elapsed 1080))
(/ parts-elapsed 1080)))
(parts ;; Conjunction parts
(+ (* 1080 (mod hours-elapsed 24)) (mod parts-elapsed 1080)))
(day ;; Conjunction day
(+ 1 (* 29 months-elapsed) (/ hours-elapsed 24)))
(alternative-day
(if (or (>= parts 19440) ;; If the new moon is at or after midday,
(and (= (mod day 7) 2);; ...or is on a Tuesday...
(>= parts 9924) ;; at 9 hours, 204 parts or later...
(not (hebrew-calendar-leap-year-p year)));; of a
;; common year,
(and (= (mod day 7) 1);; ...or is on a Monday...
(>= parts 16789) ;; at 15 hours, 589 parts or later...
(hebrew-calendar-leap-year-p (1- year))));; at the end
;; of a leap year
;; Then postpone Rosh HaShanah one day
(1+ day)
;; Else
day)))
(if ;; If Rosh HaShanah would occur on Sunday, Wednesday, or Friday
(memq (mod alternative-day 7) (list 0 3 5))
;; Then postpone it one (more) day and return
(1+ alternative-day)
;; Else return
alternative-day)))
(defun hebrew-calendar-days-in-year (year)
"Number of days in Hebrew YEAR."
(- (hebrew-calendar-elapsed-days (1+ year))
(hebrew-calendar-elapsed-days year)))
(defun hebrew-calendar-long-heshvan-p (year)
"t if Heshvan is long in Hebrew YEAR."
(= (mod (hebrew-calendar-days-in-year year) 10) 5))
(defun hebrew-calendar-short-kislev-p (year)
"t if Kislev is short in Hebrew YEAR."
(= (mod (hebrew-calendar-days-in-year year) 10) 3))
(defun calendar-absolute-from-hebrew (date)
"Absolute date of Hebrew DATE.
The absolute date is the number of days elapsed since the (imaginary)
Gregorian date Sunday, December 31, 1 BC."
(let* ((month (extract-calendar-month date))
(day (extract-calendar-day date))
(year (extract-calendar-year date)))
(+ day ;; Days so far this month.
(if (< month 7);; before Tishri
;; Then add days in prior months this year before and after Nisan
(+ (calendar-sum
m 7 (<= m (hebrew-calendar-last-month-of-year year))
(hebrew-calendar-last-day-of-month m year))
(calendar-sum
m 1 (< m month)
(hebrew-calendar-last-day-of-month m year)))
;; Else add days in prior months this year
(calendar-sum
m 7 (< m month)
(hebrew-calendar-last-day-of-month m year)))
(hebrew-calendar-elapsed-days year);; Days in prior years.
-1373429))) ;; Days elapsed before absolute date 1.reingold@m.cs.uiuc.edu (12/26/89)
;; Holiday functions.
;; Copyright (C) 1989, 1990 Free Software Foundation, Inc.
;; This file is part of GNU Emacs.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY. No author or distributor
;; accepts responsibility to anyone for the consequences of using it
;; or for whether it serves any particular purpose or works at all,
;; unless he says so in writing. Refer to the GNU Emacs General Public
;; License for full details.
;; Everyone is granted permission to copy, modify and redistribute
;; GNU Emacs, but only under the conditions described in the
;; GNU Emacs General Public License. A copy of this license is
;; supposed to have been given to you along with GNU Emacs so you
;; can know your rights and responsibilities. It should be in a
;; file named COPYING. Among other things, the copyright notice
;; and this notice must be preserved on all copies.
;; This collection of functions implements the holiday features as described
;; in calendar.el.
;; Comments, corrections, and improvements should be sent to
;; Edward M. Reingold Department of Computer Science
;; (217) 333-6733 University of Illinois at Urbana-Champaign
;; reingold@cs.uiuc.edu 1304 West Springfield Avenue
;; Urbana, Illinois 61801
;; Technical details of all of the holiday calculations can be found in
;; ``Calendrical Calculations'' by Edward M. Reingold and Nachum Dershowitz,
;; Report Number UIUCDCS-R-89-1541, Department of Computer Science,
;; University of Illinois, Urbana, Illinois, September, 1989.
(require 'calendar)
(provide 'holidays)
(defun holidays ()
"Display the holidays for last month, this month, and next month.
This function is suitable for execution in a .emacs file."
(interactive)
(save-excursion
(let* ((date (calendar-current-date))
(displayed-month (extract-calendar-month date))
(displayed-year (extract-calendar-year date)))
(list-calendar-holidays))))
(defun check-calendar-holidays (date)
"Check the list of holidays for any that occur on DATE.
The value returned is a list of strings of relevant holiday descriptions.
The holidays are those in the list calendar-holidays."
(let* ((displayed-month (extract-calendar-month date))
(displayed-year (extract-calendar-year date))
(h (calendar-holiday-list))
(holiday-list))
(while h
(if (calendar-date-equal date (car (car h)))
(setq holiday-list (append holiday-list (cdr (car h)))))
(setq h (cdr h)))
holiday-list))
(defun calendar-cursor-holidays ()
"Find holidays for the date specified by the cursor in the calendar window."
(interactive)
(message "Checking holidays...")
(let* ((date (calendar-cursor-to-date))
(date-string (calendar-date-string date))
(holiday-string
(mapconcat
'identity
(check-calendar-holidays date)
"; ")))
(if (string-equal holiday-string "")
(message "No holidays known for %s" date-string)
(message "%s: %s" date-string holiday-string))))
(defun mark-calendar-holidays ()
"Mark notable days in the calendar window."
(interactive)
(message "Marking holidays...")
(let ((holiday-list (calendar-holiday-list)))
(while holiday-list
(mark-visible-calendar-date
(car (car holiday-list)) calendar-holiday-marker)
(setq holiday-list (cdr holiday-list))))
(message "Marking holidays...done"))
(defun list-calendar-holidays ()
"Create a buffer containing the holidays for the current calendar window.
The holidays are those in the list calendar-notable-days. Returns t if any
holidays are found, nil if not."
(interactive)
(message "Looking up holidays...")
(let ((holiday-list (calendar-holiday-list))
(m1 displayed-month)
(y1 displayed-year)
(m2 displayed-month)
(y2 displayed-year))
(if (not holiday-list)
(progn
(message "Looking up holidays...none found")
nil)
(set-buffer (get-buffer-create holiday-buffer))
(setq buffer-read-only nil)
(increment-calendar-month m1 y1 -1)
(increment-calendar-month m2 y2 1)
(setq mode-line-format
(format "-------------Notable Dates from %s, %d to %s, %d%%-"
(calendar-month-name m1) y1 (calendar-month-name m2) y2))
(erase-buffer)
(insert
(mapconcat
'(lambda (x) (concat (calendar-date-string (car x))
": " (car (cdr x))))
holiday-list "\n"))
(goto-char (point-min))
(set-buffer-modified-p nil)
(setq buffer-read-only t)
(display-buffer holiday-buffer)
(message "Looking up holidays...done")
t)))
(defun calendar-holiday-list ()
"Form the list of holidays that occur on dates in the calendar window.
The holidays are those in the list calendar-holidays."
(let ((p calendar-holidays)
(holiday-list))
(while p
(let* ((function-name
(intern (format "calendar-holiday-function-%s" (car (car p)))))
(holidays
(if (cdr (car p));; optional arguments
(funcall function-name (cdr (car p)))
(funcall function-name))))
(if holidays
(setq holiday-list (append holidays holiday-list))))
(setq p (cdr p)))
(setq holiday-list (sort holiday-list 'calendar-date-compare))))
;; Below are the functions that calculate the dates of holidays; these
;; are called by the funcall in the function calendar-holiday-list. If you
;; write other such functions, be sure to imitate the style used below,
;; including the evaluation of each element in the list that constitutes
;; the argument to the function. If you don't do this evaluation, the
;; list calendar-holidays cannot contain expressions (as, for example, in
;; the entry for the Islamic new year. Also remember that each function
;; must return a list of items of the form ((month day year) string);
;; the date (month day year) should be visible in the calendar window.
(defun calendar-holiday-function-fixed (x)
"Returns the corresponding Gregorian date, if visible in the window, to
month, year where month is (car X) and year is (car (cdr X)). If it is
visible, the value returned is the list (((month day year) string)) where
string is (car (nthcdr 2 X)). Returns nil if it is not visible in the
current calendar window."
(let* ((month (car x))
(month (if (numberp month) month (eval month)))
(day (car (cdr x)))
(day (if (numberp day) day (eval day)))
(string (car (nthcdr 2 x)))
(string (if (stringp string) string (eval string)))
(m displayed-month)
(y displayed-year))
(increment-calendar-month m y (- 11 month))
(if (> m 9)
(list (list (list month day y) string)))))
(defun calendar-holiday-function-float (x)
"Returns the corresponding Gregorian date, if visible in the window, to the
n-th occurrence (negative counts from the end of the month) of dayname in
month, year where month is (car X), year is (car (cdr X)), n is
(car (nthcdr 2 X)). If it is visible, the value returned is the list
(((month day year) string)) where string is (car (nthcdr 3 X)).
Returns nil if it is not visible in the current calendar window."
(let* ((month (car x))
(month (if (numberp month) month (eval month)))
(dayname (car (cdr x)))
(dayname (if (numberp dayname) dayname (eval dayname)))
(n (car (nthcdr 2 x)))
(n (if (numberp n) n (eval n)))
(string (car (nthcdr 3 x)))
(string (if (stringp string) string (eval string)))
(m displayed-month)
(y displayed-year))
(increment-calendar-month m y (- 11 month))
(if (> m 9)
(list (list (calendar-nth-named-day n dayname month y) string)))))
(defun calendar-holiday-function-julian (x)
"Returns the corresponding Gregorian date, if visible in the window, to the
Julian date month, year where month is (car X) and year is (car (cdr X)).
If it is visible, the value returned is the list (((month day year) string))
where string is (car (nthcdr 2 X)). Returns nil if it is not visible in the
current calendar window."
(let* ((month (car x))
(month (if (numberp month) month (eval month)))
(day (car (cdr x)))
(day (if (numberp day) day (eval day)))
(string (car (nthcdr 2 x)))
(string (if (stringp string) string (eval string)))
(m1 displayed-month)
(y1 displayed-year)
(m2 displayed-month)
(y2 displayed-year)
(year))
(increment-calendar-month m1 y1 -1)
(increment-calendar-month m2 y2 1)
(let* ((start-date (calendar-absolute-from-gregorian
(list m1 1 y1)))
(end-date (calendar-absolute-from-gregorian
(list m2 (calendar-last-day-of-month m2 y2) y2)))
(julian-start (calendar-julian-from-absolute start-date))
(julian-end (calendar-julian-from-absolute end-date))
(julian-y1 (extract-calendar-year julian-start))
(julian-y2 (extract-calendar-year julian-end)))
(setq year (if (< 10 month) julian-y1 julian-y2))
(let ((date (calendar-gregorian-from-absolute
(calendar-absolute-from-julian
(list month day year)))))
(if (calendar-date-is-visible-p date)
(list (list date string)))))))
(defun calendar-holiday-function-islamic (x)
"Returns the corresponding Gregorian date, if visible in the window, to the
Islamic date month, year where month is (car X) and year is (car (cdr X)).
If it is visible, the value returned is the list (((month day year) string))
where string is (car (nthcdr 2 X)). Returns nil if it is not visible in
the current calendar window."
(let* ((month (car x))
(month (if (numberp month) month (eval month)))
(day (car (cdr x)))
(day (if (numberp day) day (eval day)))
(string (car (nthcdr 2 x)))
(string (if (stringp string) string (eval string)))
(islamic-date (calendar-islamic-from-absolute
(calendar-absolute-from-gregorian
(list displayed-month 15 displayed-year))))
(m (extract-calendar-month islamic-date))
(y (extract-calendar-year islamic-date))
(date))
(if (< m 1)
nil;; Islamic calendar doesn't apply.
(increment-calendar-month m y (- 10 month))
(if (> m 7);; Islamic date might be visible
(let ((date (calendar-gregorian-from-absolute
(calendar-absolute-from-islamic (list month day y)))))
(if (calendar-date-is-visible-p date)
(list (list date string))))))))
(defun calendar-holiday-function-hebrew (x)
"Returns the corresponding Gregorian date, if visible in the window, to the
Hebrew date month, year where month is (car X) and year is (car (cdr X)).
If it is visible, the value returned is the list (((month day year) string))
where string is (car (nthcdr 2 X)). Returns nil if it is not visible in
the current calendar window."
(let* ((month (car x))
(month (if (numberp month) month (eval month)))
(day (car (cdr x)))
(day (if (numberp day) day (eval day)))
(string (car (nthcdr 2 x)))
(string (if (stringp string) string (eval string))))
(if (memq displayed-month;; This test is only to speed things up a bit;
(list ;; it works fine without the test too.
(if (< 11 month) (- month 11) (+ month 1))
(if (< 10 month) (- month 10) (+ month 2))
(if (< 9 month) (- month 9) (+ month 3))
(if (< 8 month) (- month 8) (+ month 4))))
(let ((m1 displayed-month)
(y1 displayed-year)
(m2 displayed-month)
(y2 displayed-year)
(year))
(increment-calendar-month m1 y1 -1)
(increment-calendar-month m2 y2 1)
(let* ((start-date (calendar-absolute-from-gregorian
(list m1 1 y1)))
(end-date (calendar-absolute-from-gregorian
(list m2 (calendar-last-day-of-month m2 y2) y2)))
(hebrew-start (calendar-hebrew-from-absolute start-date))
(hebrew-end (calendar-hebrew-from-absolute end-date))
(hebrew-y1 (extract-calendar-year hebrew-start))
(hebrew-y2 (extract-calendar-year hebrew-end)))
(setq year (if (< 6 month) hebrew-y2 hebrew-y1))
(let ((date (calendar-gregorian-from-absolute
(calendar-absolute-from-hebrew
(list month day year)))))
(if (calendar-date-is-visible-p date)
(list (list date string)))))))))
(defun calendar-holiday-function-easter-etc ()
"List of dates related to Easter, as visible in calendar window."
(if (> displayed-month 5)
nil;; Ash Wednesday, Good Friday, and Easter are not visible.
(let* ((century (1+ (/ displayed-year 100)))
(shifted-epact ;; Age of moon for April 5...
(mod (+ 14 (* 11 (mod 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 (mod 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)))
(easter (calendar-gregorian-from-absolute abs-easter))
(good-friday (calendar-gregorian-from-absolute (- abs-easter 2)))
(ash-weds (calendar-gregorian-from-absolute (- abs-easter 46)))
(output-list))
(if (calendar-date-is-visible-p ash-weds)
(setq output-list (list (list ash-weds "Ash Wednesday"))))
(if (calendar-date-is-visible-p good-friday)
(setq output-list
(append (list (list good-friday "Good Friday")) output-list)))
(if (calendar-date-is-visible-p easter)
(setq output-list
(append (list (list easter "Easter Sunday")) output-list)))
output-list)))
(defun calendar-holiday-function-rosh-hashanah-etc ()
"List of dates related to Rosh Hashanah, as visible in calendar window."
(if (or (< displayed-month 8)
(> displayed-month 11))
nil;; None of the dates are visible
(let* ((abs-r-h (calendar-absolute-from-hebrew
(list 7 1 (+ displayed-year 3761))))
(rosh-h (calendar-gregorian-from-absolute abs-r-h))
(yom-k (calendar-gregorian-from-absolute (+ abs-r-h 9)))
(suc (calendar-gregorian-from-absolute (+ abs-r-h 14)))
(output-list))
(if (calendar-date-is-visible-p rosh-h)
(setq output-list
(list (list rosh-h
(format "Rosh Hashanah %d"
(+ 3761 displayed-year))))))
(if (calendar-date-is-visible-p yom-k)
(setq output-list
(append (list (list yom-k "Yom Kippur")) output-list)))
(if (calendar-date-is-visible-p suc)
(setq output-list
(append (list (list suc "Succoth")) output-list)))
output-list)))