root/trunk/lisp/calendar/calendar.el

;;; calendar.el --- calendar functions

;; Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1997,
;;   2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008  Free Software Foundation, Inc.

;; Author: Edward M. Reingold <reingold@cs.uiuc.edu>
;; Maintainer: Glenn Morris <rgm@gnu.org>
;; Keywords: calendar
;; Human-Keywords: calendar, Gregorian calendar, diary, holidays

;; This file is part of GNU Emacs.

;; GNU Emacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 3, or (at your option)
;; any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING.  If not, write to the
;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, USA.

;;; Commentary:

;; This collection of functions implements a calendar window.  It
;; 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 scrolled 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, to the
;; Islamic calendar, to the Baha'i calendar, to the French
;; Revolutionary calendar, to the Mayan calendar, to the Chinese
;; calendar, to the Coptic calendar, to the Ethiopic calendar, and to
;; the astronomical (Julian) day number.  When floating point is
;; available, times of sunrise/sunset can be displayed, as can the
;; phases of the moon.  Appointment notification for diary entries is
;; available.  Calendar printing via LaTeX is available.

;; The following files are part of the calendar/diary code:

;;       appt.el                       Appointment notification
;;       cal-china.el                  Chinese calendar
;;       cal-coptic.el                 Coptic/Ethiopic calendars
;;       cal-dst.el                    Daylight saving time rules
;;       cal-hebrew.el                 Hebrew calendar
;;       cal-islam.el                  Islamic calendar
;;       cal-bahai.el                  Baha'i calendar
;;       cal-iso.el                    ISO calendar
;;       cal-julian.el                 Julian/astronomical calendars
;;       cal-mayan.el                  Mayan calendars
;;       cal-menu.el                   Menu support
;;       cal-move.el                   Movement in the calendar
;;       cal-persia.el                 Persian calendar
;;       cal-tex.el                    Calendars in LaTeX
;;       cal-x.el                      X-windows dedicated frame functions
;;       diary-lib.el                  Diary functions
;;       holidays.el                   Holiday functions
;;       lunar.el                      Phases of the moon
;;       solar.el                      Sunrise/sunset, equinoxes/solstices

;; Technical details of all the calendrical calculations can be found in
;; ``Calendrical Calculations: The Millennium Edition'' by Edward M. Reingold
;; and Nachum Dershowitz, Cambridge University Press (2001).

;; An earlier version of the technical details appeared in
;; ``Calendrical Calculations'' by Nachum Dershowitz and Edward M. Reingold,
;; Software--Practice and Experience, Volume 20, Number 9 (September, 1990),
;; pages 899-928, and in ``Calendrical Calculations, Part II: Three Historical
;; Calendars'' by E. M. Reingold,  N. Dershowitz, and S. M. Clamen,
;; Software--Practice and Experience, Volume 23, Number 4 (April, 1993),
;; pages 383-404.

;; Hard copies of these two papers can be obtained by sending email to
;; reingold@cs.uiuc.edu with the SUBJECT "send-paper-cal" (no quotes) and
;; the message BODY containing your mailing address (snail).

;;; Code:

(defvar displayed-month)
(defvar displayed-year)
(defvar calendar-month-name-array)
(defvar calendar-starred-day)

(defun calendar-version ()
  (interactive)
  (message "Version 6, October 12, 1995"))

(defgroup calendar nil
  "Calendar and time management support."
  :group 'applications)

(defgroup diary nil
  "Emacs diary."
  :group 'calendar)

(defgroup appt nil
  "Appointment notification."
  :group 'calendar)

(defgroup holidays nil
  "Holidays support in calendar."
  :group 'calendar
  :prefix "calendar-"
  :group 'local)

(defgroup chinese-calendar nil
  "Chinese calendar support."
  :group 'calendar)

(defgroup calendar-tex nil
  "Options for printing calendar with LaTeX."
  :prefix "cal-tex-"
  :group 'calendar)

(defgroup calendar-hooks nil
  "Calendar hooks."
  :prefix "calendar-"
  :group 'calendar)


(defconst calendar-buffer "*Calendar*"
  "Name of the buffer used for the calendar.")

;;;###autoload
(defcustom calendar-offset 0
  "The offset of the principal month from the center of the calendar window.
0 means the principal month is in the center (default), -1 means on the left,
+1 means on the right.  Larger (or smaller) values push the principal month off
the screen."
  :type 'integer
  :group 'calendar)

;;;###autoload
(defcustom view-diary-entries-initially nil
  "Non-nil means display current date's diary entries on entry to calendar.
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'.  This variable can
be overridden by the value of `calendar-setup'."
  :type 'boolean
  :group 'diary)

;;;###autoload
(defcustom mark-diary-entries-in-calendar nil
  "Non-nil means mark dates with diary entries, in the calendar window.
The marking symbol is specified by the variable `diary-entry-marker'."
  :type 'boolean
  :group 'diary)

;;;###autoload
(defcustom calendar-remove-frame-by-deleting nil
  "Determine how the calendar mode removes a frame no longer needed.
If nil, make an icon of the frame.  If non-nil, delete the frame."
  :type 'boolean
  :group 'view)

(defvar diary-face 'diary
  "Face name to use for diary entries.")
(defface diary
  '((((min-colors 88) (class color) (background light))
     :foreground "red1")
    (((class color) (background light))
     :foreground "red")
    (((min-colors 88) (class color) (background dark))
     :foreground "yellow1")
    (((class color) (background dark))
     :foreground "yellow")
    (t
     :weight bold))
  "Face for highlighting diary entries."
  :group 'diary)
;; backward-compatibility alias
(put 'diary-face 'face-alias 'diary)

(defface calendar-today
  '((t (:underline t)))
  "Face for indicating today's date."
  :group 'diary)
;; backward-compatibility alias
(put 'calendar-today-face 'face-alias 'calendar-today)

(defface holiday
  '((((class color) (background light))
     :background "pink")
    (((class color) (background dark))
     :background "chocolate4")
    (t
     :inverse-video t))
  "Face for indicating dates that have holidays."
  :group 'diary)
;; backward-compatibility alias
(put 'holiday-face 'face-alias 'holiday)

(defcustom diary-entry-marker
  (if (not (display-color-p))
      "+"
    'diary)
  "How to mark dates that have diary entries.
The value can be either a single-character string or a face."
  :type '(choice string face)
  :group 'diary)

(defcustom calendar-today-marker
  (if (not (display-color-p))
      "="
    'calendar-today)
  "How to mark today's date in the calendar.
The value can be either a single-character string or a face.
Marking today's date is done only if you set up `today-visible-calendar-hook'
to request that."
  :type '(choice string face)
  :group 'calendar)

(defcustom calendar-holiday-marker
  (if (not (display-color-p))
      "*"
    'holiday)
  "How to mark notable dates in the calendar.
The value can be either a single-character string or a face."
  :type '(choice string face)
  :group 'calendar)

;;;###autoload
(defcustom view-calendar-holidays-initially nil
  "Non-nil means display holidays for current three month period on entry.
The holidays are displayed in another window when the calendar is first
displayed."
  :type 'boolean
  :group 'holidays)

;;;###autoload
(defcustom mark-holidays-in-calendar nil
  "Non-nil means mark dates of holidays in the calendar window.
The marking symbol is specified by the variable `calendar-holiday-marker'."
  :type 'boolean
  :group 'holidays)

;;;###autoload
(defcustom all-hebrew-calendar-holidays nil
  "If nil, show only major holidays from the Hebrew calendar.
This means only those Jewish holidays that appear on secular calendars.

If t, show all the holidays that would appear in a complete Hebrew calendar."
  :type 'boolean
  :group 'holidays)

;;;###autoload
(defcustom all-christian-calendar-holidays nil
  "If nil, show only major holidays from the Christian calendar.
This means only those Christian holidays that appear on secular calendars.

If t, show all the holidays that would appear in a complete Christian
calendar."
  :type 'boolean
  :group 'holidays)

;;;###autoload
(defcustom all-islamic-calendar-holidays nil
  "If nil, show only major holidays from the Islamic calendar.
This means only those Islamic holidays that appear on secular calendars.

If t, show all the holidays that would appear in a complete Islamic
calendar."
  :type 'boolean
  :group 'holidays)

(defcustom diary-file-name-prefix-function (function (lambda (str) str))
  "The function that will take a diary file name and return the desired prefix."
  :type 'function
  :group 'diary)

;;;###autoload
(defcustom all-bahai-calendar-holidays nil
  "If nil, show only major holidays from the Baha'i calendar.
These are the days on which work and school must be suspended.

If t, show all the holidays that would appear in a complete Baha'i
calendar."
  :type 'boolean
  :group 'holidays)

(defcustom calendar-mode-hook nil
  "Hook run when entering `calendar-mode'."
  :type 'hook
  :group 'calendar-hooks)

;;;###autoload
(defcustom calendar-load-hook nil
  "List of functions to be called after the calendar is first loaded.
This is the place to add key bindings to `calendar-mode-map'."
  :type 'hook
  :group 'calendar-hooks)

;;;###autoload
(defcustom 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."
  :type 'hook
  :group 'calendar-hooks)

;;;###autoload
(defcustom 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 can also be used to mark the current date with `calendar-today-marker';
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."
  :type 'hook
  :group 'calendar-hooks)

;;;###autoload
(defcustom 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."
  :type 'hook
  :group 'calendar-hooks)

;;;###autoload
(defcustom calendar-move-hook nil
  "List of functions called whenever the cursor moves in the calendar.

For example,

  (add-hook 'calendar-move-hook (lambda () (diary-view-entries 1)))

redisplays the diary for whatever date the cursor is moved to."
  :type 'hook
  :group 'calendar-hooks)

;;;###autoload
(defcustom diary-file "~/diary"
  "Name of the file in which one's personal diary of dates is kept.

The file's entries are lines beginning with any of the forms
specified by the variable `american-date-diary-pattern', by default:

            MONTH/DAY
            MONTH/DAY/YEAR
            MONTHNAME DAY
            MONTHNAME DAY, YEAR
            DAYNAME

with the remainder of the line being 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 `abbreviated-calendar-year' is non-nil).  MONTHNAME
and DAYNAME can be spelled in full (as specified by the variables
`calendar-month-name-array' and `calendar-day-name-array'),
abbreviated (as specified by `calendar-month-abbrev-array' and
`calendar-day-abbrev-array') 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. If the
date does not contain a year, it is generic and applies to any
year.  A DAYNAME entry applies to the appropriate day of the week
in every week.

The European style (in which the day precedes the month) can be
used instead, if you execute `european-calendar' when in the
calendar, or set `european-calendar-style' to t in your .emacs
file.  The European forms (see `european-date-diary-pattern') are

            DAY/MONTH
            DAY/MONTH/YEAR
            DAY MONTHNAME
            DAY MONTHNAME YEAR
            DAYNAME

To revert to the default American style from the European style, execute
`american-calendar' in the calendar.

A diary entry can be preceded by the character
`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 (in the default American style):

     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 is not displayed in the
diary window; only the continuation lines is 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 entries can be based on Lisp sexps.  For example, the diary entry

      %%(diary-block 11 1 1990 11 10 1990) Vacation

causes the diary entry \"Vacation\" to appear from November 1 through
November 10, 1990.  Other functions available are `diary-float',
`diary-anniversary', `diary-cyclic', `diary-day-of-year',
`diary-iso-date', `diary-french-date', `diary-hebrew-date',
`diary-islamic-date', `diary-bahai-date', `diary-mayan-date',
`diary-chinese-date', `diary-coptic-date', `diary-ethiopic-date',
`diary-persian-date', `diary-yahrzeit', `diary-sunrise-sunset',
`diary-phases-of-moon', `diary-parasha', `diary-omer',
`diary-rosh-hodesh', and `diary-sabbath-candles'.  See the
documentation for the function `list-sexp-diary-entries' for more
details.

Diary entries based on the Hebrew, the Islamic and/or the Baha'i
calendar are also possible, but because these are somewhat slow, they
are ignored unless you set the `nongregorian-diary-listing-hook' and
the `nongregorian-diary-marking-hook' appropriately.  See the
documentation for these functions for details.

Diary files can contain directives to include the contents of other files; for
details, see the documentation for the variable `list-diary-entries-hook'."
  :type 'file
  :group 'diary)

;;;###autoload
(defcustom diary-nonmarking-symbol "&"
  "Symbol indicating that a diary entry is not to be marked in the calendar."
  :type 'string
  :group 'diary)

;;;###autoload
(defcustom hebrew-diary-entry-symbol "H"
  "Symbol indicating a diary entry according to the Hebrew calendar."
  :type 'string
  :group 'diary)

;;;###autoload
(defcustom islamic-diary-entry-symbol "I"
  "Symbol indicating a diary entry according to the Islamic calendar."
  :type 'string
  :group 'diary)

;;;###autoload
(defcustom bahai-diary-entry-symbol "B"
  "Symbol indicating a diary entry according to the Baha'i calendar."
  :type 'string
  :group 'diary)

;;;###autoload
(defcustom diary-include-string "#include"
  "The string indicating inclusion of another file of diary entries.
See the documentation for the function `include-other-diary-files'."
  :type 'string
  :group 'diary)

(defcustom diary-glob-file-regexp-prefix "^\\#"
  "The regular expression that gets pre-pended to each of the attribute-regexp's for file-wide specifiers."
  :type 'regexp
  :group 'diary)

(defcustom diary-face-attrs
  '((" *\\[foreground:\\([-a-z]+\\)\\]$" 1 :foreground string)
    (" *\\[background:\\([-a-z]+\\)\\]$" 1 :background string)
    (" *\\[width:\\([-a-z]+\\)\\]$" 1 :width symbol)
    (" *\\[height:\\([-0-9a-z]+\\)\\]$" 1 :height int)
    (" *\\[weight:\\([-a-z]+\\)\\]$" 1 :weight symbol)
    (" *\\[slant:\\([-a-z]+\\)\\]$" 1 :slant symbol)
    (" *\\[underline:\\([-a-z]+\\)\\]$" 1 :underline stringtnil)
    (" *\\[overline:\\([-a-z]+\\)\\]$" 1 :overline stringtnil)
    (" *\\[strike-through:\\([-a-z]+\\)\\]$" 1 :strike-through stringtnil)
    (" *\\[inverse-video:\\([-a-z]+\\)\\]$" 1 :inverse-video tnil)
    (" *\\[face:\\([-0-9a-z]+\\)\\]$" 1 :face string)
    (" *\\[font:\\([-a-z0-9]+\\)\\]$" 1 :font string)
    ;; Unsupported.
;;;    (" *\\[box:\\([-a-z]+\\)\\]$" 1 :box)
;;;    (" *\\[stipple:\\([-a-z]+\\)\\]$" 1 :stipple)
    )
  "A list of (regexp regnum attr attrtype) lists where the
regexp says how to find the tag, the regnum says which
parenthetical sub-regexp this regexp looks for, and the attr says
which attribute of the face (or that this _is_ a face) is being
modified."
  :type 'sexp
  :group 'diary)

(defcustom diary-file-name-prefix nil
  "If non-nil each diary entry is prefixed with the name of the file where it is defined."
  :type 'boolean
  :group 'diary)

;;;###autoload
(defcustom sexp-diary-entry-symbol "%%"
  "The string used to indicate a sexp diary entry in `diary-file'.
See the documentation for the function `list-sexp-diary-entries'."
  :type 'string
  :group 'diary)

;;;###autoload
(defcustom abbreviated-calendar-year t
  "Interpret a two-digit year DD in a diary entry as either 19DD or 20DD.
For the Gregorian calendar; similarly for the Hebrew, Islamic and
Baha'i calendars.  If this variable is nil, years must be written in
full."
  :type 'boolean
  :group 'diary)

;;;###autoload
(defcustom 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 interpreted as February 1,
1990.  The default European date styles (see `european-date-diary-pattern')
are

            DAY/MONTH
            DAY/MONTH/YEAR
            DAY MONTHNAME
            DAY MONTHNAME YEAR
            DAYNAME

Names can be capitalized or not, written in full (as specified by the
variable `calendar-day-name-array'), or abbreviated (as specified by
`calendar-day-abbrev-array') with or without a period.

Setting this variable directly does not take effect (if the
calendar package is already loaded).  Rather, use either
\\[customize] or the functions `european-calendar' and
`american-calendar'."
  :type 'boolean
  ;; Without :initialize (require 'calendar) throws an error because
  ;; american-calendar is undefined at this point.
  :initialize 'custom-initialize-default
  :set (lambda (symbol value)
         (if value
             (european-calendar)
           (american-calendar)))
  :group 'diary)

;;;###autoload
(defcustom american-date-diary-pattern
  '((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 American patterns of date used.
See the documentation of `diary-date-forms' for an explanation."
  :type '(repeat (choice (cons :tag "Backup"
                               :value (backup . nil)
                               (const backup)
                               (repeat (list :inline t :format "%v"
                                             (symbol :tag "Keyword")
                                             (choice symbol regexp))))
                         (repeat (list :inline t :format "%v"
                                       (symbol :tag "Keyword")
                                       (choice symbol regexp)))))
  :group 'diary)

;;;###autoload
(defcustom european-date-diary-pattern
  '((day "/" month "[^/0-9]")
    (day "/" month "/" year "[^0-9]")
    (backup day " *" monthname "\\W+\\<\\([^*0-9]\\|\\([0-9]+[:aApP]\\)\\)")
    (day " *" monthname " *" year "[^0-9]")
    (dayname "\\W"))
  "List of pseudo-patterns describing the European patterns of date used.
See the documentation of `diary-date-forms' for an explanation."
  :type '(repeat (choice (cons :tag "Backup"
                               :value (backup . nil)
                               (const backup)
                               (repeat (list :inline t :format "%v"
                                             (symbol :tag "Keyword")
                                             (choice symbol regexp))))
                         (repeat (list :inline t :format "%v"
                                       (symbol :tag "Keyword")
                                       (choice symbol regexp)))))
  :group 'diary)

(autoload 'diary-font-lock-keywords "diary-lib")
(autoload 'diary-live-p "diary-lib")
(defvar diary-font-lock-keywords)

(defcustom diary-date-forms
  (if european-calendar-style
      european-date-diary-pattern
    american-date-diary-pattern)
  "List of pseudo-patterns describing the forms of date used in the diary.
The patterns on the list must be MUTUALLY EXCLUSIVE and should not match
any portion of the diary entry itself, just the date component.

A pseudo-pattern is a list of regular expressions and the keywords `month',
`day', `year', `monthname', and `dayname'.  The keyword `monthname' will
match the name of the month (see `calendar-month-name-array'), capitalized
or not, or its user-specified abbreviation (see `calendar-month-abbrev-array'),
followed by a period or not; it will also match `*'.  Similarly, `dayname'
will match the name of the day (see `calendar-day-name-array'), capitalized or
not, or its user-specified abbreviation (see `calendar-day-abbrev-array'),
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 `*'.

The matching of the diary entries with the date forms is done with the
standard syntax table from Fundamental mode, but with the `*' changed so
that it is a word constituent.

If, to be mutually exclusive, a pseudo-pattern must match a portion of the
diary entry itself, the first element of the pattern MUST be `backup'.  This
directive causes the date recognizer to back up to the beginning of the
current word of the diary entry, so in no case can the pattern match more than
a portion of the first word of the diary entry."
  :type '(repeat (choice (cons :tag "Backup"
                               :value (backup . nil)
                               (const backup)
                               (repeat (list :inline t :format "%v"
                                             (symbol :tag "Keyword")
                                             (choice symbol regexp))))
                         (repeat (list :inline t :format "%v"
                                       (symbol :tag "Keyword")
                                       (choice symbol regexp)))))
  :initialize 'custom-initialize-default
  :set (lambda (symbol value)
         (unless (equal value (eval symbol))
           (custom-set-default symbol value)
           (setq diary-font-lock-keywords (diary-font-lock-keywords))
           ;; Need to redraw not just to get new font-locking, but also
           ;; to pick up any newly recognized entries.
           (and (diary-live-p)
                (diary))))
  :group 'diary)

;;;###autoload
(defcustom european-calendar-display-form
  '((if dayname (concat dayname ", ")) day " " monthname " " year)
  "Pseudo-pattern governing the way a date appears in the European style.
See the documentation of `calendar-date-display-form' for an explanation."
  :type 'sexp
  :group 'calendar)

;;;###autoload
(defcustom american-calendar-display-form
  '((if dayname (concat dayname ", ")) monthname " " day ", " year)
  "Pseudo-pattern governing the way a date appears in the American style.
See the documentation of `calendar-date-display-form' for an explanation."
  :type 'sexp
  :group 'calendar)

(defcustom calendar-date-display-form
  (if european-calendar-style
      european-calendar-display-form
    american-calendar-display-form)
  "Pseudo-pattern governing the way a date appears.

Used by the function `calendar-date-string', a pseudo-pattern is a list of
expressions that can involve the keywords `month', `day', and `year', all
numbers in string form, and `monthname' and `dayname', both alphabetic
strings.  For example, the ISO standard would use the pseudo- pattern

       '(year \"-\" month \"-\" day)

while a typical American form would be

       '(month \"/\" day \"/\" (substring year -2))

and

       '((format \"%9s, %9s %2s, %4s\" dayname monthname day year))

would give the usual American style in fixed-length fields.

See the documentation of the function `calendar-date-string'."
  :type 'sexp
  :group 'calendar)

(defun european-calendar ()
  "Set the interpretation and display of dates to the European style."
  (interactive)
  (setq european-calendar-style t)
  (setq calendar-date-display-form european-calendar-display-form)
  (setq diary-date-forms european-date-diary-pattern)
  (update-calendar-mode-line))

(defun american-calendar ()
  "Set the interpretation and display of dates to the American style."
  (interactive)
  (setq european-calendar-style nil)
  (setq calendar-date-display-form american-calendar-display-form)
  (setq diary-date-forms american-date-diary-pattern)
  (update-calendar-mode-line))

;;;###autoload
(defcustom print-diary-entries-hook 'lpr-buffer
  "List of functions called after a temporary diary buffer is prepared.
The buffer shows only the diary entries currently visible in the diary
buffer.  The default just does the printing.  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."
  :type 'hook
  :group 'diary)

;;;###autoload
(defcustom list-diary-entries-hook nil
  "List of functions called after diary file is culled for relevant entries.
It is to be used for diary entries that are not found in the diary file.

A function `include-other-diary-files' is provided for use as the value of
this hook.  This function 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 `mark-diary-entries-hook'.

For example, you could use

     (setq list-diary-entries-hook
       '(include-other-diary-files sort-diary-entries))
     (setq diary-display-hook 'fancy-diary-display)

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."
  :type 'hook
  :options '(include-other-diary-files sort-diary-entries)
  :group 'diary)

;;;###autoload
(defcustom diary-hook nil
  "List of functions called after the display of the diary.
Can be used for appointment notification."
  :type 'hook
  :group 'diary)

(autoload 'diary-set-maybe-redraw "diary-lib")

;;;###autoload
(defcustom diary-display-hook nil
  "List of functions that handle the display of the diary.
If nil (the default), `simple-diary-display' is used.  Use `ignore' for no
diary display.

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, a different buffer for display (perhaps combined with
holidays), or produce hard copy output.

A function `fancy-diary-display' 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."
  :type 'hook
  :options '(fancy-diary-display)
  :initialize 'custom-initialize-default
  :set 'diary-set-maybe-redraw
  :group 'diary)

;;;###autoload
(defcustom nongregorian-diary-listing-hook nil
  "List of functions called for listing diary file and included files.
As the files are processed for diary entries, these functions are used
to cull relevant entries.  You can use either or both of
`list-hebrew-diary-entries', `list-islamic-diary-entries' and
`list-bahai-diary-entries'.  The documentation for these functions
describes the style of such diary ent