code.delx.au - gnu-emacs/blob - lisp/calendar/calendar.el

   1 ;;; calendar.el --- Calendar functions.
   2
   3 ;; Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1997, 2000
   4 ;;        Free Software Foundation, Inc.
   5
   6 ;; Author: Edward M. Reingold <reingold@cs.uiuc.edu>
   7 ;; Keywords: calendar
   8 ;; Human-Keywords: calendar, Gregorian calendar, diary, holidays
   9
  10 ;; This file is part of GNU Emacs.
  11
  12 ;; GNU Emacs is free software; you can redistribute it and/or modify
  13 ;; it under the terms of the GNU General Public License as published by
  14 ;; the Free Software Foundation; either version 2, or (at your option)
  15 ;; any later version.
  16
  17 ;; GNU Emacs is distributed in the hope that it will be useful,
  18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;; GNU General Public License for more details.
  21
  22 ;; You should have received a copy of the GNU General Public License
  23 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  24 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  25 ;; Boston, MA 02111-1307, USA.
  26
  27 ;;; Commentary:
  28
  29 ;; This collection of functions implements a calendar window.  It generates a
  30 ;; calendar for the current month, together with the previous and coming
  31 ;; months, or for any other three-month period.  The calendar can be scrolled
  32 ;; forward and backward in the window to show months in the past or future;
  33 ;; the cursor can move forward and backward by days, weeks, or months, making
  34 ;; it possible, for instance, to jump to the date a specified number of days,
  35 ;; weeks, or months from the date under the cursor.  The user can display a
  36 ;; list of holidays and other notable days for the period shown; the notable
  37 ;; days can be marked on the calendar, if desired.  The user can also specify
  38 ;; that dates having corresponding diary entries (in a file that the user
  39 ;; specifies) be marked; the diary entries for any date can be viewed in a
  40 ;; separate window.  The diary and the notable days can be viewed
  41 ;; independently of the calendar.  Dates can be translated from the (usual)
  42 ;; Gregorian calendar to the day of the year/days remaining in year, to the
  43 ;; ISO commercial calendar, to the Julian (old style) calendar, to the Hebrew
  44 ;; calendar, to the Islamic calendar, to the French Revolutionary calendar, to
  45 ;; the Mayan calendar, to the Chinese calendar, to the Coptic calendar, to the
  46 ;; Ethiopic calendar, and to the astronomical (Julian) day number.  When
  47 ;; floating point is available, times of sunrise/sunset can be displayed, as
  48 ;; can the phases of the moon.  Appointment notification for diary entries is
  49 ;; available.  Calendar printing via LaTeX is available.
  50
  51 ;; The following files are part of the calendar/diary code:
  52
  53 ;;       appt.el                       Appointment notification
  54 ;;       cal-china.el                  Chinese calendar
  55 ;;       cal-coptic.el                 Coptic/Ethiopic calendars
  56 ;;       cal-dst.el                    Daylight savings time rules
  57 ;;       cal-hebrew.el                 Hebrew calendar
  58 ;;       cal-islam.el                  Islamic calendar
  59 ;;       cal-iso.el                    ISO calendar
  60 ;;       cal-julian.el                 Julian/astronomical calendars
  61 ;;       cal-mayan.el                  Mayan calendars
  62 ;;       cal-menu.el                   Menu support
  63 ;;       cal-move.el                   Movement in the calendar
  64 ;;       cal-persia.el                 Persian calendar
  65 ;;       cal-tex.el                    Calendars in LaTeX
  66 ;;       cal-x.el                      X-windows dedicated frame functions
  67 ;;       diary-lib.el                  Diary functions
  68 ;;       holidays.el                   Holiday functions
  69 ;;       lunar.el                      Phases of the moon
  70 ;;       solar.el                      Sunrise/sunset, equinoxes/solstices
  71
  72 ;; Technical details of all the calendrical calculations can be found in
  73 ;; ``Calendrical Calculations'' by Nachum Dershowitz and Edward M. Reingold,
  74 ;; Cambridge University Press (1997).
  75
  76 ;; An earlier version of the technical details appeared in
  77 ;; ``Calendrical Calculations'' by Nachum Dershowitz and Edward M. Reingold,
  78 ;; Software--Practice and Experience, Volume 20, Number 9 (September, 1990),
  79 ;; pages 899-928.  ``Calendrical Calculations, Part II: Three Historical
  80 ;; Calendars'' by E. M. Reingold,  N. Dershowitz, and S. M. Clamen,
  81 ;; Software--Practice and Experience, Volume 23, Number 4 (April, 1993),
  82 ;; pages 383-404.
  83
  84 ;; Hard copies of these two papers can be obtained by sending email to
  85 ;; reingold@cs.uiuc.edu with the SUBJECT "send-paper-cal" (no quotes) and
  86 ;; the message BODY containing your mailing address (snail).
  87
  88 ;; Comments, corrections, and improvements should be sent to
  89 ;;  Edward M. Reingold               Department of Computer Science
  90 ;;  (217) 333-6733                   University of Illinois at Urbana-Champaign
  91 ;;  reingold@cs.uiuc.edu             1304 West Springfield Avenue
  92 ;;                                   Urbana, Illinois 61801
  93
  94 ;;; Code:
  95
  96 (eval-when-compile
  97   (defvar displayed-month)
  98   (defvar displayed-year)
  99   (defvar calendar-month-name-array)
 100   (defvar calendar-starred-day))
 101
 102 (defun calendar-version ()
 103   (interactive)
 104   (message "Version 6, October 12, 1995"))
 105
 106 (defgroup calendar nil
 107   "Calendar and time management support."
 108   :group 'applications)
 109
 110 (defgroup diary nil
 111   "Emacs diary."
 112   :group 'calendar)
 113
 114 (defgroup appt nil
 115   "Appointment notification."
 116   :group 'calendar)
 117
 118 (defgroup holidays nil
 119   "Holidays support in calendar."
 120   :group 'calendar
 121   :prefix "calendar-"
 122   :group 'local)
 123
 124 (defgroup chinese-calendar nil
 125   "Chinese calendar support."
 126   :group 'calendar)
 127
 128 (defgroup calendar-tex nil
 129   "Options for printing calendar with LaTeX."
 130   :prefix "cal-tex-"
 131   :group 'calendar)
 132
 133 (defgroup calendar-hooks nil
 134   "Calendar hooks."
 135   :prefix "calendar-"
 136   :group 'calendar)
 137
 138
 139 ;;;###autoload
 140 (defcustom calendar-week-start-day 0
 141   "*The day of the week on which a week in the calendar begins.
 142 0 means Sunday (default), 1 means Monday, and so on."
 143   :type 'integer
 144   :group 'calendar)
 145
 146 ;;;###autoload
 147 (defcustom calendar-offset 0
 148   "*The offset of the principal month from the center of the calendar window.
 149 0 means the principal month is in the center (default), -1 means on the left,
 150 +1 means on the right.  Larger (or smaller) values push the principal month off
 151 the screen."
 152   :type 'integer
 153   :group 'calendar)
 154
 155 ;;;###autoload
 156 (defcustom view-diary-entries-initially nil
 157   "*Non-nil means display current date's diary entries on entry.
 158 The diary is displayed in another window when the calendar is first displayed,
 159 if the current date is visible.  The number of days of diary entries displayed
 160 is governed by the variable `number-of-diary-entries'."
 161   :type 'boolean
 162   :group 'diary)
 163
 164 ;;;###autoload
 165 (defcustom number-of-diary-entries 1
 166   "*Specifies how many days of diary entries are to be displayed initially.
 167 This variable affects the diary display when the command \\[diary] is used,
 168 or if the value of the variable `view-diary-entries-initially' is t.  For
 169 example, if the default value 1 is used, then only the current day's diary
 170 entries will be displayed.  If the value 2 is used, then both the current
 171 day's and the next day's entries will be displayed.
 172
 173 The value can also be a vector such as [0 2 2 2 2 4 1]; this value
 174 says to display no diary entries on Sunday, the display the entries
 175 for the current date and the day after on Monday through Thursday,
 176 display Friday through Monday's entries on Friday, and display only
 177 Saturday's entries on Saturday.
 178
 179 This variable does not affect the diary display with the `d' command
 180 from the calendar; in that case, the prefix argument controls the
 181 number of days of diary entries displayed."
 182   :type '(choice (integer :tag "Entries")
 183                  (vector :value [0 0 0 0 0 0 0]
 184                          (integer :tag "Sunday")
 185                          (integer :tag "Monday")
 186                          (integer :tag "Tuesday")
 187                          (integer :tag "Wednesday")
 188                          (integer :tag "Thursday")
 189                          (integer :tag "Friday")
 190                          (integer :tag "Saturday")))
 191   :group 'diary)
 192
 193 ;;;###autoload
 194 (defcustom mark-diary-entries-in-calendar nil
 195   "*Non-nil means mark dates with diary entries, in the calendar window.
 196 The marking symbol is specified by the variable `diary-entry-marker'."
 197   :type 'boolean
 198   :group 'diary)
 199
 200 ;;;###autoload
 201 (defcustom calendar-remove-frame-by-deleting nil
 202   "*Determine how the calendar mode removes a frame no longer needed.
 203 If nil, make an icon of the frame.  If non-nil, delete the frame."
 204   :type 'boolean
 205   :group 'view)
 206
 207 (add-to-list 'facemenu-unlisted-faces 'diary-face)
 208 (defface diary-face
 209   '((((class color) (background light))
 210      :foreground "red")
 211     (((class color) (background dark))
 212      :foreground "yellow")
 213     (t
 214      :bold t))
 215   "Face for highlighting diary entries."
 216   :group 'diary)
 217
 218 (add-to-list 'facemenu-unlisted-faces 'calendar-today-face)
 219 (defface calendar-today-face
 220   '((t (:underline t)))
 221   "Face for indicating today's date."
 222   :group 'diary)
 223
 224 (add-to-list 'facemenu-unlisted-faces 'holiday-face)
 225 (defface holiday-face
 226   '((((class color) (background light))
 227      :background "pink")
 228     (((class color) (background dark))
 229      :background "chocolate4")
 230     (t
 231      :inverse-video t))
 232   "Face for indicating dates that have holidays."
 233   :group 'diary)
 234
 235 (defcustom diary-entry-marker
 236   (if (not window-system)
 237       "+"
 238     'diary-face)
 239   "*How to mark dates that have diary entries.
 240 The value can be either a single-character string or a face."
 241   :type '(choice string face)
 242   :group 'diary)
 243
 244 (defcustom calendar-today-marker
 245   (if (not window-system)
 246       "="
 247     'calendar-today-face)
 248   "*How to mark today's date in the calendar.
 249 The value can be either a single-character string or a face.
 250 Marking today's date is done only if you set up `today-visible-calendar-hook'
 251 to request that."
 252   :type '(choice string face)
 253   :group 'calendar)
 254
 255 (defcustom calendar-holiday-marker
 256   (if (not window-system)
 257       "*"
 258     'holiday-face)
 259   "*How to mark notable dates in the calendar.
 260 The value can be either a single-character string or a face."
 261   :type '(choice string face)
 262   :group 'calendar)
 263
 264 ;;;###autoload
 265 (defcustom view-calendar-holidays-initially nil
 266   "*Non-nil means display holidays for current three month period on entry.
 267 The holidays are displayed in another window when the calendar is first
 268 displayed."
 269   :type 'boolean
 270   :group 'holidays)
 271
 272 ;;;###autoload
 273 (defcustom mark-holidays-in-calendar nil
 274   "*Non-nil means mark dates of holidays in the calendar window.
 275 The marking symbol is specified by the variable `calendar-holiday-marker'."
 276   :type 'boolean
 277   :group 'holidays)
 278
 279 ;;;###autoload
 280 (defcustom all-hebrew-calendar-holidays nil
 281   "*If nil, show only major holidays from the Hebrew calendar.
 282 This means only those Jewish holidays that appear on secular calendars.
 283
 284 If t, show all the holidays that would appear in a complete Hebrew calendar."
 285   :type 'boolean
 286   :group 'holidays)
 287
 288 ;;;###autoload
 289 (defcustom all-christian-calendar-holidays nil
 290   "*If nil, show only major holidays from the Christian calendar.
 291 This means only those Christian holidays that appear on secular calendars.
 292
 293 If t, show all the holidays that would appear in a complete Christian
 294 calendar."
 295   :type 'boolean
 296   :group 'holidays)
 297
 298 ;;;###autoload
 299 (defcustom all-islamic-calendar-holidays nil
 300   "*If nil, show only major holidays from the Islamic calendar.
 301 This means only those Islamic holidays that appear on secular calendars.
 302
 303 If t, show all the holidays that would appear in a complete Islamic
 304 calendar."
 305   :type 'boolean
 306   :group 'holidays)
 307
 308 ;;;###autoload
 309 (defcustom calendar-load-hook nil
 310   "*List of functions to be called after the calendar is first loaded.
 311 This is the place to add key bindings to `calendar-mode-map'."
 312   :type 'hook
 313   :group 'calendar-hooks)
 314
 315 ;;;###autoload
 316 (defcustom initial-calendar-window-hook nil
 317   "*List of functions to be called when the calendar window is first opened.
 318 The functions invoked are called after the calendar window is opened, but
 319 once opened is never called again.  Leaving the calendar with the `q' command
 320 and reentering it will cause these functions to be called again."
 321   :type 'hook
 322   :group 'calendar-hooks)
 323
 324 ;;;###autoload
 325 (defcustom today-visible-calendar-hook nil
 326   "*List of functions called whenever the current date is visible.
 327 This can be used, for example, to replace today's date with asterisks; a
 328 function `calendar-star-date' is included for this purpose:
 329     (setq today-visible-calendar-hook 'calendar-star-date)
 330 It can also be used to mark the current date with `calendar-today-marker';
 331 a function is also provided for this:
 332     (setq today-visible-calendar-hook 'calendar-mark-today)
 333
 334 The corresponding variable `today-invisible-calendar-hook' is the list of
 335 functions called when the calendar function was called when the current
 336 date is not visible in the window.
 337
 338 Other than the use of the provided functions, the changing of any
 339 characters in the calendar buffer by the hooks may cause the failure of the
 340 functions that move by days and weeks."
 341   :type 'hook
 342   :group 'calendar-hooks)
 343
 344 ;;;###autoload
 345 (defcustom today-invisible-calendar-hook nil
 346   "*List of functions called whenever the current date is not visible.
 347
 348 The corresponding variable `today-visible-calendar-hook' is the list of
 349 functions called when the calendar function was called when the current
 350 date is visible in the window.
 351
 352 Other than the use of the provided functions, the changing of any
 353 characters in the calendar buffer by the hooks may cause the failure of the
 354 functions that move by days and weeks."
 355   :type 'hook
 356   :group 'calendar-hooks)
 357
 358 ;;;###autoload
 359 (defcustom calendar-move-hook nil
 360   "*List of functions called whenever the cursor moves in the calendar.
 361
 362 For example,
 363
 364   (add-hook 'calendar-move-hook (lambda () (view-diary-entries 1)))
 365
 366 redisplays the diary for whatever date the cursor is moved to."
 367   :type 'hook
 368   :group 'calendar-hooks)
 369
 370 ;;;###autoload
 371 (defcustom diary-file "~/diary"
 372   "*Name of the file in which one's personal diary of dates is kept.
 373
 374 The file's entries are lines in any of the forms
 375
 376             MONTH/DAY
 377             MONTH/DAY/YEAR
 378             MONTHNAME DAY
 379             MONTHNAME DAY, YEAR
 380             DAYNAME
 381
 382 at the beginning of the line; the remainder of the line is the diary entry
 383 string for that date.  MONTH and DAY are one or two digit numbers, YEAR is
 384 a number and may be written in full or abbreviated to the final two digits.
 385 If the date does not contain a year, it is generic and applies to any year.
 386 DAYNAME entries apply to any date on which is on that day of the week.
 387 MONTHNAME and DAYNAME can be spelled in full, abbreviated to three
 388 characters (with or without a period), capitalized or not.  Any of DAY,
 389 MONTH, or MONTHNAME, YEAR can be `*' which matches any day, month, or year,
 390 respectively.
 391
 392 The European style (in which the day precedes the month) can be used
 393 instead, if you execute `european-calendar' when in the calendar, or set
 394 `european-calendar-style' to t in your .emacs file.  The European forms are
 395
 396             DAY/MONTH
 397             DAY/MONTH/YEAR
 398             DAY MONTHNAME
 399             DAY MONTHNAME YEAR
 400             DAYNAME
 401
 402 To revert to the default American style from the European style, execute
 403 `american-calendar' in the calendar.
 404
 405 A diary entry can be preceded by the character
 406 `diary-nonmarking-symbol' (ordinarily `&') to make that entry
 407 nonmarking--that is, it will not be marked on dates in the calendar
 408 window but will appear in a diary window.
 409
 410 Multiline diary entries are made by indenting lines after the first with
 411 either a TAB or one or more spaces.
 412
 413 Lines not in one the above formats are ignored.  Here are some sample diary
 414 entries (in the default American style):
 415
 416      12/22/1988 Twentieth wedding anniversary!!
 417      &1/1. Happy New Year!
 418      10/22 Ruth's birthday.
 419      21: Payday
 420      Tuesday--weekly meeting with grad students at 10am
 421               Supowit, Shen, Bitner, and Kapoor to attend.
 422      1/13/89 Friday the thirteenth!!
 423      &thu 4pm squash game with Lloyd.
 424      mar 16 Dad's birthday
 425      April 15, 1989 Income tax due.
 426      &* 15 time cards due.
 427
 428 If the first line of a diary entry consists only of the date or day name with
 429 no trailing blanks or punctuation, then that line is not displayed in the
 430 diary window; only the continuation lines is shown.  For example, the
 431 single diary entry
 432
 433      02/11/1989
 434       Bill Blattner visits Princeton today
 435       2pm Cognitive Studies Committee meeting
 436       2:30-5:30 Lizzie at Lawrenceville for `Group Initiative'
 437       4:00pm Jamie Tappenden
 438       7:30pm Dinner at George and Ed's for Alan Ryan
 439       7:30-10:00pm dance at Stewart Country Day School
 440
 441 will appear in the diary window without the date line at the beginning.  This
 442 facility allows the diary window to look neater, but can cause confusion if
 443 used with more than one day's entries displayed.
 444
 445 Diary entries can be based on Lisp sexps.  For example, the diary entry
 446
 447       %%(diary-block 11 1 1990 11 10 1990) Vacation
 448
 449 causes the diary entry \"Vacation\" to appear from November 1 through November
 450 10, 1990.  Other functions available are `diary-float', `diary-anniversary',
 451 `diary-cyclic', `diary-day-of-year', `diary-iso-date', `diary-french-date',
 452 `diary-hebrew-date', `diary-islamic-date', `diary-mayan-date',
 453 `diary-chinese-date', `diary-coptic-date', `diary-ethiopic-date',
 454 `diary-persian-date', `diary-yahrzeit', `diary-sunrise-sunset',
 455 `diary-phases-of-moon', `diary-parasha', `diary-omer', `diary-rosh-hodesh',
 456 and `diary-sabbath-candles'.  See the documentation for the function
 457 `list-sexp-diary-entries' for more details.
 458
 459 Diary entries based on the Hebrew and/or the Islamic calendar are also
 460 possible, but because these are somewhat slow, they are ignored
 461 unless you set the `nongregorian-diary-listing-hook' and the
 462 `nongregorian-diary-marking-hook' appropriately.  See the documentation
 463 for these functions for details.
 464
 465 Diary files can contain directives to include the contents of other files; for
 466 details, see the documentation for the variable `list-diary-entries-hook'."
 467   :type 'file
 468   :group 'diary)
 469
 470 ;;;###autoload
 471 (defcustom diary-nonmarking-symbol "&"
 472   "*Symbol indicating that a diary entry is not to be marked in the calendar."
 473   :type 'string
 474   :group 'diary)
 475
 476 ;;;###autoload
 477 (defcustom hebrew-diary-entry-symbol "H"
 478   "*Symbol indicating a diary entry according to the Hebrew calendar."
 479   :type 'string
 480   :group 'diary)
 481
 482 ;;;###autoload
 483 (defcustom islamic-diary-entry-symbol "I"
 484   "*Symbol indicating a diary entry according to the Islamic calendar."
 485   :type 'string
 486   :group 'diary)
 487
 488 ;;;###autoload
 489 (defcustom diary-include-string "#include"
 490   "*The string indicating inclusion of another file of diary entries.
 491 See the documentation for the function `include-other-diary-files'."
 492   :type 'string
 493   :group 'diary)
 494
 495 ;;;###autoload
 496 (defcustom sexp-diary-entry-symbol "%%"
 497   "*The string used to indicate a sexp diary entry in `diary-file'.
 498 See the documentation for the function `list-sexp-diary-entries'."
 499   :type 'string
 500   :group 'diary)
 501
 502 ;;;###autoload
 503 (defcustom abbreviated-calendar-year t
 504   "*Interpret a two-digit year DD in a diary entry as either 19DD or 20DD.
 505 For the Gregorian calendar; similarly for the Hebrew and Islamic calendars.
 506 If this variable is nil, years must be written in full."
 507   :type 'boolean
 508   :group 'diary)
 509
 510 ;;;###autoload
 511 (defcustom european-calendar-style nil
 512   "*Use the European style of dates in the diary and in any displays.
 513 If this variable is t, a date 1/2/1990 would be interpreted as February 1,
 514 1990.  The accepted European date styles are
 515
 516             DAY/MONTH
 517             DAY/MONTH/YEAR
 518             DAY MONTHNAME
 519             DAY MONTHNAME YEAR
 520             DAYNAME
 521
 522 Names can be capitalized or not, written in full, or abbreviated to three
 523 characters with or without a period."
 524   :type 'boolean
 525   :group 'diary)
 526
 527 ;;;###autoload
 528 (defcustom american-date-diary-pattern
 529   '((month "/" day "[^/0-9]")
 530     (month "/" day "/" year "[^0-9]")
 531     (monthname " *" day "[^,0-9]")
 532     (monthname " *" day ", *" year "[^0-9]")
 533     (dayname "\\W"))
 534   "*List of pseudo-patterns describing the American patterns of date used.
 535 See the documentation of `diary-date-forms' for an explanation."
 536   :type '(repeat (choice (cons :tag "Backup"
 537                                :value (backup . nil)
 538                                (const backup)
 539                                (repeat (list :inline t :format "%v"
 540                                              (symbol :tag "Keyword")
 541                                              (choice symbol regexp))))
 542                          (repeat (list :inline t :format "%v"
 543                                        (symbol :tag "Keyword")
 544                                        (choice symbol regexp)))))
 545   :group 'diary)
 546
 547 ;;;###autoload
 548 (defcustom european-date-diary-pattern
 549   '((day "/" month "[^/0-9]")
 550     (day "/" month "/" year "[^0-9]")
 551     (backup day " *" monthname "\\W+\\<\\([^*0-9]\\|\\([0-9]+[:aApP]\\)\\)")
 552     (day " *" monthname " *" year "[^0-9]")
 553     (dayname "\\W"))
 554   "*List of pseudo-patterns describing the European patterns of date used.
 555 See the documentation of `diary-date-forms' for an explanation."
 556   :type '(repeat (choice (cons :tag "Backup"
 557                                :value (backup . nil)
 558                                (const backup)
 559                                (repeat (list :inline t :format "%v"
 560                                              (symbol :tag "Keyword")
 561                                              (choice symbol regexp))))
 562                          (repeat (list :inline t :format "%v"
 563                                        (symbol :tag "Keyword")
 564                                        (choice symbol regexp)))))
 565   :group 'diary)
 566
 567 (defcustom diary-date-forms
 568   (if european-calendar-style
 569       european-date-diary-pattern
 570     american-date-diary-pattern)
 571   "*List of pseudo-patterns describing the forms of date used in the diary.
 572 The patterns on the list must be MUTUALLY EXCLUSIVE and must should not match
 573 any portion of the diary entry itself, just the date component.
 574
 575 A pseudo-pattern is a list of regular expressions and the keywords `month',
 576 `day', `year', `monthname', and `dayname'.  The keyword `monthname' will
 577 match the name of the month, capitalized or not, or its three-letter
 578 abbreviation, followed by a period or not; it will also match `*'.
 579 Similarly, `dayname' will match the name of the day, capitalized or not, or
 580 its three-letter abbreviation, followed by a period or not.  The keywords
 581 `month', `day', and `year' will match those numerical values, preceded by
 582 arbitrarily many zeros; they will also match `*'.
 583
 584 The matching of the diary entries with the date forms is done with the
 585 standard syntax table from Fundamental mode, but with the `*' changed so
 586 that it is a word constituent.
 587
 588 If, to be mutually exclusive, a pseudo-pattern must match a portion of the
 589 diary entry itself, the first element of the pattern MUST be `backup'.  This
 590 directive causes the date recognizer to back up to the beginning of the
 591 current word of the diary entry, so in no case can the pattern match more than
 592 a portion of the first word of the diary entry."
 593   :type '(repeat (choice (cons :tag "Backup"
 594                                :value (backup . nil)
 595                                (const backup)
 596                                (repeat (list :inline t :format "%v"
 597                                              (symbol :tag "Keyword")
 598                                              (choice symbol regexp))))
 599                          (repeat (list :inline t :format "%v"
 600                                        (symbol :tag "Keyword")
 601                                        (choice symbol regexp)))))
 602   :group 'diary)
 603
 604 ;;;###autoload
 605 (defcustom european-calendar-display-form
 606   '((if dayname (concat dayname ", ")) day " " monthname " " year)
 607   "*Pseudo-pattern governing the way a date appears in the European style.
 608 See the documentation of calendar-date-display-form for an explanation."
 609   :type 'sexp
 610   :group 'calendar)
 611
 612 ;;;###autoload
 613 (defcustom american-calendar-display-form
 614   '((if dayname (concat dayname ", ")) monthname " " day ", " year)
 615   "*Pseudo-pattern governing the way a date appears in the American style.
 616 See the documentation of `calendar-date-display-form' for an explanation."
 617   :type 'sexp
 618   :group 'calendar)
 619
 620 (defcustom calendar-date-display-form
 621   (if european-calendar-style
 622       european-calendar-display-form
 623     american-calendar-display-form)
 624   "*Pseudo-pattern governing the way a date appears.
 625
 626 Used by the function `calendar-date-string', a pseudo-pattern is a list of
 627 expressions that can involve the keywords `month', `day', and `year', all
 628 numbers in string form, and `monthname' and `dayname', both alphabetic
 629 strings.  For example, the ISO standard would use the pseudo- pattern
 630
 631        '(year \"-\" month \"-\" day)
 632
 633 while a typical American form would be
 634
 635        '(month \"/\" day \"/\" (substring year -2))
 636
 637 and
 638
 639        '((format \"%9s, %9s %2s, %4s\" dayname monthname day year))
 640
 641 would give the usual American style in fixed-length fields.
 642
 643 See the documentation of the function `calendar-date-string'."
 644   :type 'sexp
 645   :group 'calendar)
 646
 647 (defun european-calendar ()
 648   "Set the interpretation and display of dates to the European style."
 649   (interactive)
 650   (setq european-calendar-style t)
 651   (setq calendar-date-display-form european-calendar-display-form)
 652   (setq diary-date-forms european-date-diary-pattern)
 653   (update-calendar-mode-line))
 654
 655 (defun american-calendar ()
 656   "Set the interpretation and display of dates to the American style."
 657   (interactive)
 658   (setq european-calendar-style nil)
 659   (setq calendar-date-display-form american-calendar-display-form)
 660   (setq diary-date-forms american-date-diary-pattern)
 661   (update-calendar-mode-line))
 662
 663 ;;;###autoload
 664 (defcustom print-diary-entries-hook 'lpr-buffer
 665   "*List of functions called after a temporary diary buffer is prepared.
 666 The buffer shows only the diary entries currently visible in the diary
 667 buffer.  The default just does the printing.  Other uses might include, for
 668 example, rearranging the lines into order by day and time, saving the buffer
 669 instead of deleting it, or changing the function used to do the printing."
 670   :type 'hook
 671   :group 'diary)
 672
 673 ;;;###autoload
 674 (defcustom list-diary-entries-hook nil
 675   "*List of functions called after diary file is culled for relevant entries.
 676 It is to be used for diary entries that are not found in the diary file.
 677
 678 A function `include-other-diary-files' is provided for use as the value of
 679 this hook.  This function enables you to use shared diary files together
 680 with your own.  The files included are specified in the diary file by lines
 681 of the form
 682
 683         #include \"filename\"
 684
 685 This is recursive; that is, #include directives in files thus included are
 686 obeyed.  You can change the \"#include\" to some other string by changing
 687 the variable `diary-include-string'.  When you use `include-other-diary-files'
 688 as part of the list-diary-entries-hook, you will probably also want to use the
 689 function `mark-included-diary-files' as part of `mark-diary-entries-hook'.
 690
 691 For example, you could use
 692
 693      (setq list-diary-entries-hook
 694        '(include-other-diary-files sort-diary-entries))
 695      (setq diary-display-hook 'fancy-diary-display)
 696
 697 in your `.emacs' file to cause the fancy diary buffer to be displayed with
 698 diary entries from various included files, each day's entries sorted into
 699 lexicographic order."
 700   :type 'hook
 701   :group 'diary)
 702
 703 ;;;###autoload
 704 (defcustom diary-hook nil
 705   "*List of functions called after the display of the diary.
 706 Can be used for appointment notification."
 707   :type 'hook
 708   :group 'diary)
 709
 710 ;;;###autoload
 711 (defcustom diary-display-hook nil
 712   "*List of functions that handle the display of the diary.
 713 If nil (the default), `simple-diary-display' is used.  Use `ignore' for no
 714 diary display.
 715
 716 Ordinarily, this just displays the diary buffer (with holidays indicated in
 717 the mode line), if there are any relevant entries.  At the time these
 718 functions are called, the variable `diary-entries-list' is a list, in order
 719 by date, of all relevant diary entries in the form of ((MONTH DAY YEAR)
 720 STRING), where string is the diary entry for the given date.  This can be
 721 used, for example, a different buffer for display (perhaps combined with
 722 holidays), or produce hard copy output.
 723
 724 A function `fancy-diary-display' is provided as an alternative
 725 choice for this hook; this function prepares a special noneditable diary
 726 buffer with the relevant diary entries that has neat day-by-day arrangement
 727 with headings.  The fancy diary buffer will show the holidays unless the
 728 variable `holidays-in-diary-buffer' is set to nil.  Ordinarily, the fancy
 729 diary buffer will not show days for which there are no diary entries, even
 730 if that day is a holiday; if you want such days to be shown in the fancy
 731 diary buffer, set the variable `diary-list-include-blanks' to t."
 732   :type 'hook
 733   :group 'diary)
 734
 735 ;;;###autoload
 736 (defcustom nongregorian-diary-listing-hook nil
 737   "*List of functions called for listing diary file and included files.
 738 As the files are processed for diary entries, these functions are used to cull
 739 relevant entries.  You can use either or both of `list-hebrew-diary-entries'
 740 and `list-islamic-diary-entries'.  The documentation for these functions
 741 describes the style of such diary entries."
 742   :type 'hook
 743   :group 'diary)
 744
 745 ;;;###autoload
 746 (defcustom mark-diary-entries-hook nil
 747   "*List of functions called after marking diary entries in the calendar.
 748
 749 A function `mark-included-diary-files' is also provided for use as the
 750 `mark-diary-entries-hook'; it enables you to use shared diary files together
 751 with your own.  The files included are specified in the diary file by lines
 752 of the form
 753         #include \"filename\"
 754 This is recursive; that is, #include directives in files thus included are
 755 obeyed.  You can change the \"#include\" to some other string by changing the
 756 variable `diary-include-string'.  When you use `mark-included-diary-files' as
 757 part of the mark-diary-entries-hook, you will probably also want to use the
 758 function `include-other-diary-files' as part of `list-diary-entries-hook'."
 759   :type 'hook
 760   :group 'diary)
 761
 762 ;;;###autoload
 763 (defcustom nongregorian-diary-marking-hook nil
 764   "*List of functions called for marking diary file and included files.
 765 As the files are processed for diary entries, these functions are used to cull
 766 relevant entries.  You can use either or both of `mark-hebrew-diary-entries'
 767 and `mark-islamic-diary-entries'.  The documentation for these functions
 768 describes the style of such diary entries."
 769   :type 'hook
 770   :group 'diary)
 771
 772 ;;;###autoload
 773 (defcustom diary-list-include-blanks nil
 774   "*If nil, do not include days with no diary entry in the list of diary entries.
 775 Such days will then not be shown in the fancy diary buffer, even if they
 776 are holidays."
 777   :type 'boolean
 778   :group 'diary)
 779
 780 ;;;###autoload
 781 (defcustom holidays-in-diary-buffer t
 782   "*Non-nil means include holidays in the diary display.
 783 The holidays appear in the mode line of the diary buffer, or in the
 784 fancy diary buffer next to the date.  This slows down the diary functions
 785 somewhat; setting it to nil makes the diary display faster."
 786   :type 'boolean
 787   :group 'holidays)
 788
 789 (defvar calendar-mark-ring nil)
 790
 791 ;;;###autoload
 792 (put 'general-holidays 'risky-local-variable t)
 793 ;;;###autoload
 794 (defcustom general-holidays
 795   '((holiday-fixed 1 1 "New Year's Day")
 796     (holiday-float 1 1 3 "Martin Luther King Day")
 797     (holiday-fixed 2 2 "Groundhog Day")
 798     (holiday-fixed 2 14 "Valentine's Day")
 799     (holiday-float 2 1 3 "President's Day")
 800     (holiday-fixed 3 17 "St. Patrick's Day")
 801     (holiday-fixed 4 1 "April Fools' Day")
 802     (holiday-float 5 0 2 "Mother's Day")
 803     (holiday-float 5 1 -1 "Memorial Day")
 804     (holiday-fixed 6 14 "Flag Day")
 805     (holiday-float 6 0 3 "Father's Day")
 806     (holiday-fixed 7 4 "Independence Day")
 807     (holiday-float 9 1 1 "Labor Day")
 808     (holiday-float 10 1 2 "Columbus Day")
 809     (holiday-fixed 10 31 "Halloween")
 810     (holiday-fixed 11 11 "Veteran's Day")
 811     (holiday-float 11 4 4 "Thanksgiving"))
 812   "*General holidays.  Default value is for the United States.
 813 See the documentation for `calendar-holidays' for details."
 814   :type 'sexp
 815   :group 'holidays)
 816
 817 ;;;###autoload
 818 (put 'oriental-holidays 'risky-local-variable t)
 819 ;;;###autoload
 820 (defcustom oriental-holidays
 821   '((if (fboundp 'atan)
 822         (holiday-chinese-new-year)))
 823   "*Oriental holidays.
 824 See the documentation for `calendar-holidays' for details."
 825   :type 'sexp
 826   :group 'holidays)
 827
 828 ;;;###autoload
 829 (put 'local-holidays 'risky-local-variable t)
 830 ;;;###autoload
 831 (defcustom local-holidays nil
 832   "*Local holidays.
 833 See the documentation for `calendar-holidays' for details."
 834   :type 'sexp
 835   :group 'holidays)
 836
 837 ;;;###autoload
 838 (put 'other-holidays 'risky-local-variable t)
 839 ;;;###autoload
 840 (defcustom other-holidays nil
 841   "*User defined holidays.
 842 See the documentation for `calendar-holidays' for details."
 843   :type 'sexp
 844   :group 'holidays)
 845
 846 ;;;###autoload
 847 (put 'hebrew-holidays-1 'risky-local-variable t)
 848 ;;;###autoload
 849 (defvar hebrew-holidays-1
 850   '((holiday-rosh-hashanah-etc)
 851     (if all-hebrew-calendar-holidays
 852         (holiday-julian
 853          11
 854          (let* ((m displayed-month)
 855                 (y displayed-year)
 856                 (year))
 857            (increment-calendar-month m y -1)
 858            (let ((year (extract-calendar-year
 859                         (calendar-julian-from-absolute
 860                          (calendar-absolute-from-gregorian
 861                           (list m 1 y))))))
 862              (if (zerop (% (1+ year) 4))
 863                  22
 864                21))) "\"Tal Umatar\" (evening)"))))
 865
 866 ;;;###autoload
 867 (put 'hebrew-holidays-2 'risky-local-variable t)
 868 ;;;###autoload
 869 (defvar hebrew-holidays-2
 870   '((if all-hebrew-calendar-holidays
 871         (holiday-hanukkah)
 872       (holiday-hebrew 9 25 "Hanukkah"))
 873     (if all-hebrew-calendar-holidays
 874       (holiday-hebrew
 875        10
 876        (let ((h-year (extract-calendar-year
 877                       (calendar-hebrew-from-absolute
 878                        (calendar-absolute-from-gregorian
 879                         (list displayed-month 28 displayed-year))))))
 880          (if (= (% (calendar-absolute-from-hebrew (list 10 10 h-year))
 881                    7)
 882                 6)
 883              11 10))
 884        "Tzom Teveth"))
 885     (if all-hebrew-calendar-holidays
 886         (holiday-hebrew 11 15 "Tu B'Shevat"))))
 887
 888 ;;;###autoload
 889 (put 'hebrew-holidays-3 'risky-local-variable t)
 890 ;;;###autoload
 891 (defvar hebrew-holidays-3
 892   '((if all-hebrew-calendar-holidays
 893         (holiday-hebrew
 894          11
 895          (let ((m displayed-month)
 896                (y displayed-year))
 897            (increment-calendar-month m y 1)
 898            (let* ((h-year (extract-calendar-year
 899                            (calendar-hebrew-from-absolute
 900                             (calendar-absolute-from-gregorian
 901                              (list m
 902                                    (calendar-last-day-of-month m y)
 903                                    y)))))
 904                   (s-s
 905                    (calendar-hebrew-from-absolute
 906                     (if (=
 907                          (% (calendar-absolute-from-hebrew
 908                              (list 7 1 h-year))
 909                             7)
 910                          6)
 911                         (calendar-dayname-on-or-before
 912                          6 (calendar-absolute-from-hebrew
 913                             (list 11 17 h-year)))
 914                       (calendar-dayname-on-or-before
 915                        6 (calendar-absolute-from-hebrew
 916                           (list 11 16 h-year))))))
 917                   (day (extract-calendar-day s-s)))
 918              day))
 919          "Shabbat Shirah"))))
 920
 921 ;;;###autoload
 922 (put 'hebrew-holidays-4 'risky-local-variable t)
 923 ;;;###autoload
 924 (defvar hebrew-holidays-4
 925   '((holiday-passover-etc)
 926     (if (and all-hebrew-calendar-holidays
 927              (let* ((m displayed-month)
 928                     (y displayed-year)
 929                     (year))
 930                (increment-calendar-month m y -1)
 931                (let ((year (extract-calendar-year
 932                             (calendar-julian-from-absolute
 933                              (calendar-absolute-from-gregorian
 934                               (list m 1 y))))))
 935                  (= 21 (% year 28)))))
 936         (holiday-julian 3 26 "Kiddush HaHamah"))
 937     (if all-hebrew-calendar-holidays
 938         (holiday-tisha-b-av-etc))))
 939
 940 ;;;###autoload
 941 (put 'hebrew-holidays 'risky-local-variable t)
 942 ;;;###autoload
 943 (defcustom hebrew-holidays (append hebrew-holidays-1 hebrew-holidays-2
 944                                 hebrew-holidays-3 hebrew-holidays-4)
 945   "*Jewish holidays.
 946 See the documentation for `calendar-holidays' for details."
 947   :type 'sexp
 948   :group 'holidays)
 949
 950 ;;;###autoload
 951 (put 'christian-holidays 'risky-local-variable t)
 952 ;;;###autoload
 953 (defcustom christian-holidays
 954   '((if all-christian-calendar-holidays
 955         (holiday-fixed 1 6 "Epiphany"))
 956     (holiday-easter-etc)
 957     (if all-christian-calendar-holidays
 958         (holiday-greek-orthodox-easter))
 959     (if all-christian-calendar-holidays
 960         (holiday-fixed 8 15 "Assumption"))
 961     (if all-christian-calendar-holidays
 962         (holiday-advent))
 963     (holiday-fixed 12 25 "Christmas")
 964     (if all-christian-calendar-holidays
 965         (holiday-julian 12 25 "Eastern Orthodox Christmas")))
 966   "*Christian holidays.
 967 See the documentation for `calendar-holidays' for details."
 968   :type 'sexp
 969   :group 'holidays)
 970
 971 ;;;###autoload
 972 (put 'islamic-holidays 'risky-local-variable t)
 973 ;;;###autoload
 974 (defcustom islamic-holidays
 975   '((holiday-islamic
 976      1 1
 977      (format "Islamic New Year %d"
 978              (let ((m displayed-month)
 979                    (y displayed-year))
 980                (increment-calendar-month m y 1)
 981                (extract-calendar-year
 982                 (calendar-islamic-from-absolute
 983                  (calendar-absolute-from-gregorian
 984                   (list
 985                    m (calendar-last-day-of-month m y) y)))))))
 986     (if all-islamic-calendar-holidays
 987         (holiday-islamic 1 10 "Ashura"))
 988     (if all-islamic-calendar-holidays
 989         (holiday-islamic 3 12 "Mulad-al-Nabi"))
 990     (if all-islamic-calendar-holidays
 991         (holiday-islamic 7 26 "Shab-e-Mi'raj"))
 992     (if all-islamic-calendar-holidays
 993         (holiday-islamic 8 15 "Shab-e-Bara't"))
 994     (holiday-islamic 9 1 "Ramadan Begins")
 995     (if all-islamic-calendar-holidays
 996         (holiday-islamic 9 27 "Shab-e Qadr"))
 997     (if all-islamic-calendar-holidays
 998         (holiday-islamic 10 1 "Id-al-Fitr"))
 999     (if all-islamic-calendar-holidays
1000         (holiday-islamic 12 10 "Id-al-Adha")))
1001   "*Islamic holidays.
1002 See the documentation for `calendar-holidays' for details."
1003   :type 'sexp
1004   :group 'holidays)
1005
1006 ;;;###autoload
1007 (put 'solar-holidays 'risky-local-variable t)
1008 ;;;###autoload
1009 (defcustom solar-holidays
1010   '((if (fboundp 'atan)
1011         (solar-equinoxes-solstices))
1012     (if (progn
1013           (require 'cal-dst)
1014           t)
1015       (funcall
1016        'holiday-sexp
1017         calendar-daylight-savings-starts
1018         '(format "Daylight Savings Time Begins %s"
1019                   (if (fboundp 'atan)
1020                       (solar-time-string
1021                        (/ calendar-daylight-savings-starts-time (float 60))
1022                        calendar-standard-time-zone-name)
1023                     ""))))
1024     (funcall
1025      'holiday-sexp
1026      calendar-daylight-savings-ends
1027      '(format "Daylight Savings Time Ends %s"
1028               (if (fboundp 'atan)
1029                   (solar-time-string
1030                    (/ calendar-daylight-savings-ends-time (float 60))
1031                    calendar-daylight-time-zone-name)
1032                 ""))))
1033   "*Sun-related holidays.
1034 See the documentation for `calendar-holidays' for details."
1035   :type 'sexp
1036   :group 'holidays)
1037
1038 ;;;###autoload
1039 (put 'calendar-holidays 'risky-local-variable t)
1040 (defcustom calendar-holidays
1041   (append general-holidays local-holidays other-holidays
1042           christian-holidays hebrew-holidays islamic-holidays
1043           oriental-holidays solar-holidays)
1044   "*List of notable days for the command \\[holidays].
1045
1046 Additional holidays are easy to add to the list, just put them in the list
1047 `other-holidays' in your .emacs file.  Similarly, by setting any of
1048 `general-holidays', `local-holidays' `christian-holidays', `hebrew-holidays',
1049 `islamic-holidays', `oriental-holidays', or `solar-holidays' to nil in your
1050 .emacs file, you can eliminate unwanted categories of holidays.  The intention
1051 is that (in the US) `local-holidays' be set in site-init.el and
1052 `other-holidays' be set by the user.
1053
1054 Entries on the list are expressions that return (possibly empty) lists of
1055 items of the form ((month day year) string) of a holiday in the in the
1056 three-month period centered around `displayed-month' of `displayed-year'.
1057 Several basic functions are provided for this purpose:
1058
1059     (holiday-fixed MONTH DAY STRING) is a fixed date on the Gregorian calendar
1060     (holiday-float MONTH DAYNAME K STRING &optional day) is the Kth DAYNAME in
1061                                MONTH on the Gregorian calendar (0 for Sunday,
1062                                etc.); K<0 means count back from the end of the
1063                                month.  An optional parameter DAY means the Kth
1064                                DAYNAME after/before MONTH DAY.
1065     (holiday-hebrew MONTH DAY STRING)  a fixed date on the Hebrew calendar
1066     (holiday-islamic MONTH DAY STRING) a fixed date on the Islamic calendar
1067     (holiday-julian MONTH DAY STRING)  a fixed date on the Julian calendar
1068     (holiday-sexp SEXP STRING) SEXP is a Gregorian-date-valued expression
1069                                in the variable `year'; if it evaluates to
1070                                a visible date, that's the holiday; if it
1071                                evaluates to nil, there's no holiday.  STRING
1072                                is an expression in the variable `date'.
1073
1074 For example, to add Bastille Day, celebrated in France on July 14, add
1075
1076      (holiday-fixed 7 14 \"Bastille Day\")
1077
1078 to the list.  To add Hurricane Supplication Day, celebrated in the Virgin
1079 Islands on the fourth Monday in August, add
1080
1081      (holiday-float 8 1 4 \"Hurricane Supplication Day\")
1082
1083 to the list (the last Monday would be specified with `-1' instead of `4').
1084 To add the last day of Hanukkah to the list, use
1085
1086      (holiday-hebrew 10 2 \"Last day of Hanukkah\")
1087
1088 since the Hebrew months are numbered with 1 starting from Nisan, while to
1089 add the Islamic feast celebrating Mohammed's birthday use
1090
1091      (holiday-islamic 3 12 \"Mohammed's Birthday\")
1092
1093 since the Islamic months are numbered from 1 starting with Muharram.  To
1094 add Thomas Jefferson's birthday, April 2, 1743 (Julian), use
1095
1096      (holiday-julian 4 2 \"Jefferson's Birthday\")
1097
1098 To include a holiday conditionally, use the sexp form or a conditional.  For
1099 example, to include American presidential elections, which occur on the first
1100 Tuesday after the first Monday in November of years divisible by 4, add
1101
1102      (holiday-sexp
1103        (if (zerop (% year 4))
1104            (calendar-gregorian-from-absolute
1105              (1+ (calendar-dayname-on-or-before
1106                    1 (+ 6 (calendar-absolute-from-gregorian
1107                             (list 11 1 year)))))))
1108        \"US Presidential Election\")
1109
1110 or
1111
1112      (if (zerop (% displayed-year 4))
1113          (holiday-fixed 11
1114                 (extract-calendar-day
1115                  (calendar-gregorian-from-absolute
1116                   (1+ (calendar-dayname-on-or-before
1117                        1 (+ 6 (calendar-absolute-from-gregorian
1118                                (list 11 1 displayed-year)))))))
1119                 \"US Presidential Election\"))
1120
1121 to the list.  To include the phases of the moon, add
1122
1123      (lunar-phases)
1124
1125 to the holiday list, where `lunar-phases' is an Emacs-Lisp function that
1126 you've written to return a (possibly empty) list of the relevant VISIBLE dates
1127 with descriptive strings such as
1128
1129      (((2 6 1989) \"New Moon\") ((2 12 1989) \"First Quarter Moon\") ... )."
1130   :type 'sexp
1131   :group 'holidays)
1132
1133 (defconst calendar-buffer "*Calendar*"
1134   "Name of the buffer used for the calendar.")
1135
1136 (defconst holiday-buffer "*Holidays*"
1137   "Name of the buffer used for the displaying the holidays.")
1138
1139 (defconst fancy-diary-buffer "*Fancy Diary Entries*"
1140   "Name of the buffer used for the optional fancy display of the diary.")
1141
1142 (defconst other-calendars-buffer "*Other Calendars*"
1143   "Name of the buffer used for the display of date on other calendars.")
1144
1145 (defconst lunar-phases-buffer "*Phases of Moon*"
1146   "Name of the buffer used for the lunar phases.")
1147
1148 (defmacro increment-calendar-month (mon yr n)
1149   "Move the variables MON and YR to the month and year by N months.
1150 Forward if N is positive or backward if N is negative."
1151   `(let ((macro-y (+ (* ,yr 12) ,mon -1 ,n)))
1152     (setq ,mon (1+ (% macro-y 12)))
1153     (setq ,yr (/ macro-y 12))))
1154
1155 (defmacro calendar-for-loop (var from init to final do &rest body)
1156   "Execute a for loop."
1157   `(let ((,var (1- ,init)))
1158     (while (>= ,final (setq ,var (1+ ,var)))
1159       ,@body)))
1160
1161 (defmacro calendar-sum (index initial condition expression)
1162   "For INDEX = INITIAL et seq, as long as CONDITION holds, sum EXPRESSION."
1163   `(let ((,index ,initial)
1164          (sum 0))
1165     (while ,condition
1166       (setq sum (+ sum ,expression))
1167       (setq ,index (1+ ,index)))
1168     sum))
1169
1170 ;; The following are in-line for speed; they can be called thousands of times
1171 ;; when looking up holidays or processing the diary.  Here, for example, are
1172 ;; the numbers of calls to calendar/diary/holiday functions in preparing the
1173 ;; fancy diary display, for a moderately complex diary file, with functions
1174 ;; used instead of macros.  There were a total of 10000 such calls:
1175 ;;
1176 ;;  1934   extract-calendar-month
1177 ;;  1852   extract-calendar-year
1178 ;;  1819   extract-calendar-day
1179 ;;   845   calendar-leap-year-p
1180 ;;   837   calendar-day-number
1181 ;;   775   calendar-absolute-from-gregorian
1182 ;;   346   calendar-last-day-of-month
1183 ;;   286   hebrew-calendar-last-day-of-month
1184 ;;   188   hebrew-calendar-leap-year-p
1185 ;;   180   hebrew-calendar-elapsed-days
1186 ;;   163   hebrew-calendar-last-month-of-year
1187 ;;    66   calendar-date-compare
1188 ;;    65   hebrew-calendar-days-in-year
1189 ;;    60   calendar-absolute-from-julian
1190 ;;    50   calendar-absolute-from-hebrew
1191 ;;    43   calendar-date-equal
1192 ;;    38   calendar-gregorian-from-absolute
1193 ;;     .
1194 ;;     .
1195 ;;     .
1196 ;;
1197 ;; The use of these seven macros eliminates the overhead of 92% of the function
1198 ;; calls; it's faster this way.
1199
1200 (defsubst extract-calendar-month (date)
1201   "Extract the month part of DATE which has the form (month day year)."
1202   (car date))
1203
1204 (defsubst extract-calendar-day (date)
1205   "Extract the day part of DATE which has the form (month day year)."
1206   (car (cdr date)))
1207
1208 (defsubst extract-calendar-year (date)
1209   "Extract the year part of DATE which has the form (month day year)."
1210   (car (cdr (cdr date))))
1211
1212 (defsubst calendar-leap-year-p (year)
1213   "Return t if YEAR is a Gregorian leap year."
1214   (and (zerop (% year 4))
1215        (or (not (zerop (% year 100)))
1216            (zerop (% year 400)))))
1217
1218 ;; The foregoing is a bit faster, but not as clear as the following:
1219 ;;
1220 ;;(defsubst calendar-leap-year-p (year)
1221 ;;  "Returns t if YEAR is a Gregorian leap year."
1222 ;;  (or
1223 ;;    (and (=  (% year   4) 0)
1224 ;;         (/= (% year 100) 0))
1225 ;;    (= (% year 400) 0)))
1226
1227 (defsubst calendar-last-day-of-month (month year)
1228   "The last day in MONTH during YEAR."
1229   (if (and (= month 2) (calendar-leap-year-p year))
1230       29
1231     (aref [31 28 31 30 31 30 31 31 30 31 30 31] (1- month))))
1232
1233 ;; An explanation of the calculation can be found in PascAlgorithms by
1234 ;; Edward and Ruth Reingold, Scott-Foresman/Little, Brown, 1988.
1235
1236 (defsubst calendar-day-number (date)
1237   "Return the day number within the year of the date DATE.
1238 For example, (calendar-day-number '(1 1 1987)) returns the value 1,
1239 while (calendar-day-number '(12 31 1980)) returns 366."
1240     (let* ((month (extract-calendar-month date))
1241            (day (extract-calendar-day date))
1242            (year (extract-calendar-year date))
1243          (day-of-year (+ day (* 31 (1- month)))))
1244       (if (> month 2)
1245           (progn
1246             (setq day-of-year (- day-of-year (/ (+ 23 (* 4 month)) 10)))
1247             (if (calendar-leap-year-p year)
1248                 (setq day-of-year (1+ day-of-year)))))
1249       day-of-year))
1250
1251 (defsubst calendar-absolute-from-gregorian (date)
1252   "The number of days elapsed between the Gregorian date 12/31/1 BC and DATE.
1253 The Gregorian date Sunday, December 31, 1 BC is imaginary."
1254   (let ((prior-years (1- (extract-calendar-year date))))
1255     (+ (calendar-day-number date);; Days this year
1256        (* 365 prior-years);;        + Days in prior years
1257        (/ prior-years 4);;          + Julian leap years
1258        (- (/ prior-years 100));;    - century years
1259        (/ prior-years 400))));;     + Gregorian leap years
1260
1261 (autoload 'calendar-goto-today "cal-move"
1262   "Reposition the calendar window so the current date is visible."
1263   t)
1264
1265 (autoload 'calendar-forward-month "cal-move"
1266   "Move the cursor forward ARG months."
1267   t)
1268
1269 (autoload 'calendar-forward-year "cal-move"
1270   "Move the cursor forward by ARG years."
1271   t)
1272
1273 (autoload 'calendar-backward-month "cal-move"
1274   "Move the cursor backward by ARG months."
1275   t)
1276
1277 (autoload 'calendar-backward-year "cal-move"
1278   "Move the cursor backward ARG years."
1279   t)
1280
1281 (autoload 'scroll-calendar-left "cal-move"
1282   "Scroll the displayed calendar left by ARG months."
1283   t)
1284
1285 (autoload 'scroll-calendar-right "cal-move"
1286   "Scroll the displayed calendar window right by ARG months."
1287   t)
1288
1289 (autoload 'scroll-calendar-left-three-months "cal-move"
1290   "Scroll the displayed calendar window left by 3*ARG months."
1291   t)
1292
1293 (autoload 'scroll-calendar-right-three-months "cal-move"
1294   "Scroll the displayed calendar window right by 3*ARG months."
1295   t)
1296
1297 (autoload 'calendar-cursor-to-nearest-date "cal-move"
1298   "Move the cursor to the closest date."
1299   t)
1300
1301 (autoload 'calendar-forward-day "cal-move"
1302   "Move the cursor forward ARG days."
1303   t)
1304
1305 (autoload 'calendar-backward-day "cal-move"
1306   "Move the cursor back ARG days."
1307   t)
1308
1309 (autoload 'calendar-forward-week "cal-move"
1310   "Move the cursor forward ARG weeks."
1311   t)
1312
1313 (autoload 'calendar-backward-week "cal-move"
1314   "Move the cursor back ARG weeks."
1315   t)
1316
1317 (autoload 'calendar-beginning-of-week "cal-move"
1318   "Move the cursor back ARG calendar-week-start-day's."
1319   t)
1320
1321 (autoload 'calendar-end-of-week "cal-move"
1322   "Move the cursor forward ARG calendar-week-start-day+6's."
1323   t)
1324
1325 (autoload 'calendar-beginning-of-month "cal-move"
1326   "Move the cursor backward ARG month beginnings."
1327   t)
1328
1329 (autoload 'calendar-end-of-month "cal-move"
1330   "Move the cursor forward ARG month ends."
1331   t)
1332
1333 (autoload 'calendar-beginning-of-year "cal-move"
1334   "Move the cursor backward ARG year beginnings."
1335   t)
1336
1337 (autoload 'calendar-end-of-year "cal-move"
1338   "Move the cursor forward ARG year beginnings."
1339   t)
1340
1341 (autoload 'calendar-cursor-to-visible-date "cal-move"
1342   "Move the cursor to DATE that is on the screen."
1343   t)
1344
1345 (autoload 'calendar-goto-date "cal-move"
1346   "Move cursor to DATE."
1347   t)
1348
1349 (autoload 'calendar-one-frame-setup "cal-x"
1350   "Start calendar and display it in a dedicated frame together with the diary.")
1351
1352 (autoload 'calendar-two-frame-setup "cal-x"
1353   "Start calendar and diary in separate, dedicated frames.")
1354
1355 ;;;###autoload
1356 (defvar calendar-setup nil
1357   "The frame set up of the calendar.
1358 The choices are `one-frame' (calendar and diary together in one separate,
1359 dedicated frame), `two-frames' (calendar and diary in separate, dedicated
1360 frames), `calendar-only' (calendar in a separate, dedicated frame); with
1361 any other value the current frame is used.")
1362
1363 ;;;###autoload
1364 (defun calendar (&optional arg)
1365   "Choose between the one frame, two frame, or basic calendar displays.
1366 The original function `calendar' has been renamed `calendar-basic-setup'."
1367   (interactive "P")
1368   (cond ((equal calendar-setup 'one-frame) (calendar-one-frame-setup arg))
1369         ((equal calendar-setup 'two-frames) (calendar-two-frame-setup arg))
1370         ((equal calendar-setup 'calendar-only)
1371          (calendar-only-one-frame-setup arg))
1372         (t (calendar-basic-setup arg))))
1373
1374 (defun calendar-basic-setup (&optional arg)
1375   "Display a three-month calendar in another window.
1376 The three months appear side by side, with the current month in the middle
1377 surrounded by the previous and next months.  The cursor is put on today's date.
1378
1379 If called with an optional prefix argument, prompts for month and year.
1380
1381 This function is suitable for execution in a .emacs file; appropriate setting
1382 of the variable `view-diary-entries-initially' will cause the diary entries for
1383 the current date to be displayed in another window.  The value of the variable
1384 `number-of-diary-entries' controls the number of days of diary entries
1385 displayed upon initial display of the calendar.
1386
1387 An optional prefix argument ARG causes the calendar displayed to be ARG
1388 months in the future if ARG is positive or in the past if ARG is negative;
1389 in this case the cursor goes on the first day of the month.
1390
1391 Once in the calendar window, future or past months can be moved into view.
1392 Arbitrary months can be displayed, or the calendar can be scrolled forward
1393 or backward.
1394
1395 The cursor can be moved forward or backward by one day, one week, one month,
1396 or one year.  All of these commands take prefix arguments which, when negative,
1397 cause movement in the opposite direction.  For convenience, the digit keys
1398 and the minus sign are automatically prefixes.  The window is replotted as
1399 necessary to display the desired date.
1400
1401 Diary entries can be marked on the calendar or displayed in another window.
1402
1403 Use \\[describe-mode] for details of the key bindings in the calendar window.
1404
1405 The Gregorian calendar is assumed.
1406
1407 After loading the calendar, the hooks given by the variable
1408 `calendar-load-hook' are run.  This is the place to add key bindings to the
1409 calendar-mode-map.
1410
1411 After preparing the calendar window initially, the hooks given by the variable
1412 `initial-calendar-window-hook' are run.
1413
1414 The hooks given by the variable `today-visible-calendar-hook' are run
1415 every time the calendar window gets scrolled, if the current date is visible
1416 in the window.  If it is not visible, the hooks given by the variable
1417 `today-invisible-calendar-hook' are run.  Thus, for example, setting
1418 `today-visible-calendar-hook' to 'calendar-star-date will cause today's date
1419 to be replaced by asterisks to highlight it whenever it is in the window."
1420   (interactive "P")
1421   (set-buffer (get-buffer-create calendar-buffer))
1422   (calendar-mode)
1423   (let* ((pop-up-windows t)
1424          (split-height-threshold 1000)
1425          (date (if arg
1426                    (calendar-read-date t)
1427                  (calendar-current-date)))
1428          (month (extract-calendar-month date))
1429          (year (extract-calendar-year date)))
1430     (pop-to-buffer calendar-buffer)
1431     (increment-calendar-month month year (- calendar-offset))
1432     (generate-calendar-window month year)
1433     (if (and view-diary-entries-initially (calendar-date-is-visible-p date))
1434         (view-diary-entries
1435          (if (vectorp number-of-diary-entries)
1436              (aref number-of-diary-entries (calendar-day-of-week date))
1437            number-of-diary-entries))))
1438   (let* ((diary-buffer (get-file-buffer diary-file))
1439          (diary-window (if diary-buffer (get-buffer-window diary-buffer)))
1440          (split-height-threshold (if diary-window 2 1000)))
1441     (if view-calendar-holidays-initially
1442         (list-calendar-holidays)))
1443   (run-hooks 'initial-calendar-window-hook))
1444
1445 (autoload 'view-diary-entries "diary-lib"
1446   "Prepare and display a buffer with diary entries.
1447 Searches your diary file for entries that match ARG days starting with
1448 the date indicated by the cursor position in the displayed three-month
1449 calendar."
1450   t)
1451
1452 (autoload 'calendar-sunrise-sunset "solar"
1453   "Local time of sunrise and sunset for date under cursor."
1454   t)
1455
1456 (autoload 'calendar-phases-of-moon "lunar"
1457   "Create a buffer of the phases of the moon for the current calendar window."
1458   t)
1459
1460 (autoload 'calendar-print-french-date "cal-french"
1461   "Show the French Revolutionary calendar equivalent of the date under the cursor."
1462   t)
1463
1464 (autoload 'calendar-goto-french-date "cal-french"
1465  "Move cursor to French Revolutionary date."
1466   t)
1467
1468 (autoload 'calendar-french-date-string "cal-french"
1469   "String of French Revolutionary date of Gregorian date."
1470   t)
1471
1472 (autoload 'calendar-mayan-date-string "cal-mayan"
1473   "String of Mayan date of Gregorian date."
1474   t)
1475
1476 (autoload 'calendar-print-mayan-date "cal-mayan"
1477   "Show the Mayan long count, Tzolkin, and Haab equivalents of the date under the cursor."
1478   t)
1479
1480 (autoload 'calendar-goto-mayan-long-count-date "cal-mayan"
1481  "Move cursor to Mayan long count date."
1482   t)
1483
1484 (autoload 'calendar-next-haab-date "cal-mayan"
1485   "Move cursor to next instance of Mayan Haab date."
1486   t)
1487
1488 (autoload 'calendar-previous-haab-date "cal-mayan"
1489   "Move cursor to previous instance of Mayan Haab date."
1490   t)
1491
1492 (autoload 'calendar-next-tzolkin-date "cal-mayan"
1493   "Move cursor to next instance of Mayan Tzolkin date."
1494   t)
1495
1496 (autoload 'calendar-previous-tzolkin-date "cal-mayan"
1497   "Move cursor to previous instance of Mayan Tzolkin date."
1498   t)
1499
1500 (autoload 'calendar-next-calendar-round-date "cal-mayan"
1501   "Move cursor to next instance of Mayan Haab/Tzolkin combination."
1502   t)
1503
1504 (autoload 'calendar-previous-calendar-round-date "cal-mayan"
1505   "Move cursor to previous instance of Mayan Haab/Tzolkin combination."
1506   t)
1507
1508 (autoload 'calendar-goto-chinese-date "cal-china"
1509    "Move cursor to Chinese date."
1510    t)
1511
1512 (autoload 'calendar-print-chinese-date "cal-china"
1513  "Show the Chinese date equivalents of date."
1514  t)
1515
1516 (autoload 'calendar-chinese-date-string "cal-china"
1517   "String of Chinese date of Gregorian date."
1518   t)
1519
1520 (autoload 'calendar-absolute-from-astro  "cal-julian"
1521   "Absolute date of astronomical (Julian) day number D."
1522   t )
1523
1524 (autoload 'calendar-astro-from-absolute "cal-julian"
1525   "Astronomical (Julian) day number of absolute date D.")
1526
1527 (autoload 'calendar-astro-date-string "cal-julian"
1528   "String of astronomical (Julian) day number of Gregorian date."
1529   t)
1530
1531 (autoload 'calendar-goto-astro-day-number "cal-julian"
1532    "Move cursor to astronomical (Julian) day number."
1533    t)
1534
1535 (autoload 'calendar-print-astro-day-number "cal-julian"
1536    "Show the astro date equivalents of date."
1537    t)
1538
1539 (autoload 'calendar-julian-from-absolute "cal-julian"
1540   "Compute the Julian (month day year) corresponding to the absolute DATE.
1541 The absolute date is the number of days elapsed since the (imaginary)
1542 Gregorian date Sunday, December 31, 1 BC.")
1543
1544 (autoload 'calendar-goto-julian-date "cal-julian"
1545   "Move cursor to Julian DATE; echo Julian date unless NOECHO is t."
1546   t)
1547
1548 (autoload 'calendar-print-julian-date "cal-julian"
1549   "Show the Julian calendar equivalent of the date under the cursor."
1550   t)
1551
1552 (autoload 'calendar-julian-date-string "cal-julian"
1553   "String of Julian date of Gregorian DATE.
1554 Defaults to today's date if DATE is not given.
1555 Driven by the variable `calendar-date-display-form'.")
1556
1557 (autoload 'calendar-goto-iso-date "cal-iso"
1558   "Move cursor to ISO date."
1559   t)
1560
1561 (autoload 'calendar-print-iso-date "cal-iso"
1562   "Show the ISO date equivalents of date."
1563   t)
1564
1565 (autoload 'calendar-iso-date-string "cal-iso"
1566   "String of ISO date of Gregorian date."
1567   t)
1568
1569 (autoload 'calendar-print-islamic-date "cal-islam"
1570   "Show the Islamic date equivalents of date."
1571   t)
1572
1573 (autoload 'calendar-islamic-date-string "cal-islam"
1574   "String of Islamic date of Gregorian date."
1575   t)
1576
1577 (autoload 'calendar-goto-hebrew-date "cal-hebrew"
1578   "Move cursor to Hebrew date date."
1579   t)
1580
1581 (autoload 'calendar-print-hebrew-date "cal-hebrew"
1582   "Show the Hebrew date equivalents of date."
1583   t)
1584
1585 (autoload 'calendar-hebrew-date-string "cal-hebrew"
1586   "String of Hebrew date of Gregorian date."
1587   t)
1588
1589 (autoload 'calendar-goto-coptic-date "cal-coptic"
1590    "Move cursor to Coptic date date."
1591    t)
1592
1593 (autoload 'calendar-print-coptic-date "cal-coptic"
1594  "Show the Coptic date equivalents of date."
1595  t)
1596
1597 (autoload 'calendar-coptic-date-string "cal-coptic"
1598   "String of Coptic date of Gregorian date."
1599   t)
1600
1601 (autoload 'calendar-goto-ethiopic-date "cal-coptic"
1602    "Move cursor to Ethiopic date date."
1603    t)
1604
1605 (autoload 'calendar-print-ethiopic-date "cal-coptic"
1606  "Show the Ethiopic date equivalents of date."
1607  t)
1608
1609 (autoload 'calendar-ethiopic-date-string "cal-coptic"
1610   "String of Ethiopic date of Gregorian date."
1611   t)
1612
1613 (autoload 'calendar-goto-persian-date "cal-persia"
1614    "Move cursor to Persian date date."
1615    t)
1616
1617 (autoload 'calendar-print-persian-date "cal-persia"
1618  "Show the Persian date equivalents of date."
1619  t)
1620
1621 (autoload 'calendar-persian-date-string "cal-persia"
1622   "String of Persian date of Gregorian date."
1623   t)
1624
1625 (autoload 'show-all-diary-entries "diary-lib"
1626   "Show all of the diary entries in the diary file.
1627 This function gets rid of the selective display of the diary file so that
1628 all entries, not just some, are visible.  If there is no diary buffer, one
1629 is created."
1630   t)
1631
1632 (autoload 'mark-diary-entries "diary-lib"
1633   "Mark days in the calendar window that have diary entries.
1634 Each entry in diary file visible in the calendar window is marked."
1635   t)
1636
1637 (autoload 'make-diary-entry "diary-lib"
1638   "Insert a diary entry STRING which may be NONMARKING in FILE."
1639   t)
1640
1641 (autoload 'insert-diary-entry "diary-lib"
1642   "Insert a diary entry for the date indicated by point."
1643   t)
1644
1645 (autoload 'insert-weekly-diary-entry "diary-lib"
1646   "Insert a weekly diary entry for the day of the week indicated by point."
1647   t)
1648
1649
1650 (autoload 'insert-monthly-diary-entry "diary-lib"
1651   "Insert a monthly diary entry for the day of the month indicated by point."
1652   t)
1653
1654 (autoload 'insert-yearly-diary-entry "diary-lib"
1655   "Insert an annual diary entry for the day of the year indicated by point."
1656   t)
1657
1658 (autoload 'insert-anniversary-diary-entry "diary-lib"
1659   "Insert an anniversary diary entry for the date indicated by point."
1660   t)
1661
1662 (autoload 'insert-block-diary-entry "diary-lib"
1663   "Insert a block diary entry for the dates indicated by point and mark."
1664   t)
1665
1666 (autoload 'insert-cyclic-diary-entry "diary-lib"
1667   "Insert a cyclic diary entry starting at the date indicated by point."
1668   t)
1669
1670 (autoload 'insert-hebrew-diary-entry "cal-hebrew"
1671   "Insert a diary entry for the Hebrew date corresponding to the date
1672 indicated by point."
1673   t)
1674
1675 (autoload 'insert-monthly-hebrew-diary-entry "cal-hebrew"
1676   "Insert a monthly diary entry for the day of the Hebrew month corresponding
1677 to the date indicated by point."
1678   t)
1679
1680 (autoload 'insert-yearly-hebrew-diary-entry "cal-hebrew"
1681   "Insert an annual diary entry for the day of the Hebrew year corresponding
1682 to the date indicated by point."
1683   t)
1684
1685 (autoload 'insert-islamic-diary-entry "cal-islam"
1686   "Insert a diary entry for the Islamic date corresponding to the date
1687 indicated by point."
1688   t)
1689
1690 (autoload 'insert-monthly-islamic-diary-entry "cal-islam"
1691   "Insert a monthly diary entry for the day of the Islamic month corresponding
1692 to the date indicated by point."
1693   t)
1694
1695 (autoload 'insert-yearly-islamic-diary-entry "cal-islam"
1696   "Insert an annual diary entry for the day of the Islamic year corresponding
1697 to the date indicated by point."
1698   t)
1699
1700 (autoload 'list-calendar-holidays "holidays"
1701   "Create a buffer containing the holidays for the current calendar window.
1702 The holidays are those in the list `calendar-notable-days'.  Returns t if any
1703 holidays are found, nil if not."
1704   t)
1705
1706 (autoload 'cal-tex-cursor-month "cal-tex"
1707   "Make a buffer with LaTeX commands for the month cursor is on.
1708 Optional prefix argument specifies number of months to be produced.
1709 Calendar is condensed onto one page.")
1710
1711 (autoload 'cal-tex-cursor-month-landscape "cal-tex"
1712   "Make a buffer with LaTeX commands for the month cursor is on.
1713 Optional prefix argument specifies number of months to be produced.")
1714
1715 (autoload 'cal-tex-cursor-day "cal-tex"
1716   "Make a buffer with LaTeX commands for the day cursor is on.")
1717
1718 (autoload 'cal-tex-cursor-week "cal-tex"
1719   "Make a buffer with LaTeX commands for a two-page one-week calendar.
1720 It applies to the week that point is in.
1721 Optional prefix argument specifies number of weeks.
1722 Holidays are included if `cal-tex-holidays' is t.")
1723
1724 (autoload 'cal-tex-cursor-week2 "cal-tex"
1725   "Make a buffer with LaTeX commands for a two-page one-week calendar.
1726 It applies to the week that point is in.
1727 Optional prefix argument specifies number of weeks.
1728 Holidays are included if `cal-tex-holidays' is t.")
1729
1730 (autoload 'cal-tex-cursor-week-iso "cal-tex"
1731   "Make a buffer with LaTeX commands for a one page ISO-style weekly calendar.
1732 Optional prefix argument specifies number of weeks.
1733 Diary entries are included if `cal-tex-diary' is t.
1734 Holidays are included if `cal-tex-holidays' is t.")
1735
1736 (autoload 'cal-tex-cursor-week-monday "cal-tex"
1737   "Make a buffer with LaTeX commands for a two-page one-week calendar.
1738 It applies to the week that point is in, and starts on Monday.
1739 Optional prefix argument specifies number of weeks.
1740 Holidays are included if `cal-tex-holidays' is t.")
1741
1742 (autoload 'cal-tex-cursor-filofax-2week "cal-tex"
1743   "Two-weeks-at-a-glance Filofax style calendar for week indicated by cursor.
1744 Optional prefix argument specifies number of weeks.
1745 Diary entries are included if cal-tex-diary is t.
1746 Holidays are included if `cal-tex-holidays' is t.")
1747
1748 (autoload 'cal-tex-cursor-filofax-week "cal-tex"
1749   "One-week-at-a-glance Filofax style calendar for week indicated by cursor.
1750 Optional prefix argument specifies number of weeks.
1751 Weeks start on Monday.
1752 Diary entries are included if cal-tex-diary is t.
1753 Holidays are included if `cal-tex-holidays' is t.")
1754
1755 (autoload 'cal-tex-cursor-filofax-daily "cal-tex"
1756   "Day-per-page Filofax style calendar for week indicated by cursor.
1757 Optional prefix argument specifies number of weeks.  Weeks start on Monday.
1758 Diary entries are included if `cal-tex-diary' is t.
1759 Holidays are included if `cal-tex-holidays' is t.")
1760
1761 (autoload 'cal-tex-cursor-year "cal-tex"
1762   "Make a buffer with LaTeX commands for a year's calendar.
1763 Optional prefix argument specifies number of years.")
1764
1765 (autoload 'cal-tex-cursor-year-landscape "cal-tex"
1766   "Make a buffer with LaTeX commands for a year's calendar (landscape).
1767 Optional prefix argument specifies number of years.")
1768
1769 (autoload 'cal-tex-cursor-filofax-year "cal-tex"
1770   "Make a buffer with LaTeX commands for a year's calendar (Filofax).
1771 Optional prefix argument specifies number of years.")
1772
1773 (autoload 'mark-calendar-holidays "holidays"
1774   "Mark notable days in the calendar window."
1775   t)
1776
1777 (autoload 'calendar-cursor-holidays "holidays"
1778   "Find holidays for the date specified by the cursor in the calendar window."
1779   t)
1780
1781 (defun generate-calendar-window (&optional mon yr)
1782   "Generate the calendar window for the current date.
1783 Or, for optional MON, YR."
1784   (let* ((buffer-read-only nil)
1785          (today (calendar-current-date))
1786          (month (extract-calendar-month today))
1787          (day (extract-calendar-day today))
1788          (year (extract-calendar-year today))
1789          (today-visible
1790           (or (not mon)
1791               (let ((offset (calendar-interval mon yr month year)))
1792                 (and (<= offset 1) (>= offset -1)))))
1793          (day-in-week (calendar-day-of-week today)))
1794     (update-calendar-mode-line)
1795     (if mon
1796         (generate-calendar mon yr)
1797         (generate-calendar month year))
1798     (calendar-cursor-to-visible-date
1799      (if today-visible today (list displayed-month 1 displayed-year)))
1800     (set-buffer-modified-p nil)
1801     (if (or (one-window-p t) (/= (frame-width) (window-width)))
1802         ;; Don't mess with the window size, but ensure that the first
1803         ;; line is fully visible
1804         (set-window-vscroll nil 0)
1805       ;; Adjust the window to exactly fit the displayed calendar
1806       (fit-window-to-buffer))
1807     (sit-for 0)
1808     (and mark-holidays-in-calendar
1809          (mark-calendar-holidays)
1810          (sit-for 0))
1811     (unwind-protect
1812         (if mark-diary-entries-in-calendar (mark-diary-entries))
1813       (if today-visible
1814           (run-hooks 'today-visible-calendar-hook)
1815         (run-hooks 'today-invisible-calendar-hook)))))
1816
1817 (defun generate-calendar (month year)
1818   "Generate a three-month Gregorian calendar centered around MONTH, YEAR."
1819   (if (< (+ month (* 12 (1- year))) 2)
1820       (error "Months before February, 1 AD are not available."))
1821   (setq displayed-month month)
1822   (setq displayed-year year)
1823   (erase-buffer)
1824   (increment-calendar-month month year -1)
1825   (calendar-for-loop i from 0 to 2 do
1826        (generate-calendar-month month year (+ 5 (* 25 i)))
1827        (increment-calendar-month month year 1)))
1828
1829 (defun generate-calendar-month (month year indent)
1830   "Produce a calendar for MONTH, YEAR on the Gregorian calendar.
1831 The calendar is inserted in the buffer starting at the line on which point
1832 is currently located, but indented INDENT spaces.  The indentation is done
1833 from the first character on the line and does not disturb the first INDENT
1834 characters on the line."
1835   (let* ((blank-days;; at start of month
1836           (mod
1837            (- (calendar-day-of-week (list month 1 year))
1838               calendar-week-start-day)
1839            7))
1840          (last (calendar-last-day-of-month month year)))
1841    (goto-char (point-min))
1842    (calendar-insert-indented
1843     (calendar-string-spread
1844      (list (format "%s %d" (calendar-month-name month) year)) ?  20)
1845     indent t)
1846    (calendar-insert-indented "" indent);; Go to proper spot
1847    (calendar-for-loop i from 0 to 6 do
1848       (insert (calendar-day-name (mod (+ calendar-week-start-day i) 7)
1849                                  2 t))
1850       (insert " "))
1851    (calendar-insert-indented "" 0 t);; Force onto following line
1852    (calendar-insert-indented "" indent);; Go to proper spot
1853    ;; Add blank days before the first of the month
1854    (calendar-for-loop i from 1 to blank-days do (insert "   "))
1855    ;; Put in the days of the month
1856    (calendar-for-loop i from 1 to last do
1857       (insert (format "%2d " i))
1858       (put-text-property (- (point) 3) (1- (point))
1859                          'mouse-face 'highlight)
1860       (and (zerop (mod (+ i blank-days) 7))
1861            (/= i last)
1862            (calendar-insert-indented "" 0 t)    ;; Force onto following line
1863            (calendar-insert-indented "" indent)))));; Go to proper spot
1864
1865 (defun calendar-insert-indented (string indent &optional newline)
1866   "Insert STRING at column INDENT.
1867 If the optional parameter NEWLINE is t, leave point at start of next line,
1868 inserting a newline if there was no next line; otherwise, leave point after
1869 the inserted text.  Value is always t."
1870   ;; Try to move to that column.
1871   (move-to-column indent)
1872   ;; If line is too short, indent out to that column.
1873   (if (< (current-column) indent)
1874       (indent-to indent))
1875   (insert string)
1876   ;; Advance to next line, if requested.
1877   (if newline
1878       (progn
1879         (end-of-line)
1880         (if (eobp)
1881             (newline)
1882           (forward-line 1))))
1883   t)
1884
1885 (defun redraw-calendar ()
1886   "Redraw the calendar display."
1887   (interactive)
1888   (let ((cursor-date (calendar-cursor-to-nearest-date)))
1889     (generate-calendar-window displayed-month displayed-year)
1890     (calendar-cursor-to-visible-date cursor-date)))
1891
1892 (defcustom calendar-debug-sexp nil
1893   "*Turn debugging on when evaluating a sexp in the diary or holiday list."
1894   :type 'boolean
1895   :group 'calendar)
1896
1897 (defvar calendar-mode-map nil)
1898 (if calendar-mode-map
1899     nil
1900   (setq calendar-mode-map (make-sparse-keymap))
1901   (if window-system (require 'cal-menu))
1902   (calendar-for-loop i from 0 to 9 do
1903        (define-key calendar-mode-map (int-to-string i) 'digit-argument))
1904   (let ((l (list 'narrow-to-region 'mark-word 'mark-sexp 'mark-paragraph
1905                  'mark-defun 'mark-whole-buffer 'mark-page
1906                  'downcase-region 'upcase-region 'kill-region
1907                  'copy-region-as-kill 'capitalize-region 'write-region)))
1908     (while l
1909       (substitute-key-definition (car l) 'calendar-not-implemented
1910                                  calendar-mode-map global-map)
1911       (setq l (cdr l))))
1912   (define-key calendar-mode-map "-"     'negative-argument)
1913   (define-key calendar-mode-map "\C-x>" 'scroll-calendar-right)
1914   (define-key calendar-mode-map [prior] 'scroll-calendar-right-three-months)
1915   (define-key calendar-mode-map "\ev"   'scroll-calendar-right-three-months)
1916   (define-key calendar-mode-map "\C-x<" 'scroll-calendar-left)
1917   (define-key calendar-mode-map [next]  'scroll-calendar-left-three-months)
1918   (define-key calendar-mode-map "\C-v"  'scroll-calendar-left-three-months)
1919   (define-key calendar-mode-map "\C-b"  'calendar-backward-day)
1920   (define-key calendar-mode-map "\C-p"  'calendar-backward-week)
1921   (define-key calendar-mode-map "\e{"   'calendar-backward-month)
1922   (define-key calendar-mode-map "\C-x[" 'calendar-backward-year)
1923   (define-key calendar-mode-map "\C-f"  'calendar-forward-day)
1924   (define-key calendar-mode-map "\C-n"  'calendar-forward-week)
1925   (define-key calendar-mode-map [left]  'calendar-backward-day)
1926   (define-key calendar-mode-map [up]    'calendar-backward-week)
1927   (define-key calendar-mode-map [right] 'calendar-forward-day)
1928   (define-key calendar-mode-map [down]  'calendar-forward-week)
1929   (define-key calendar-mode-map "\e}"   'calendar-forward-month)
1930   (define-key calendar-mode-map "\C-x]" 'calendar-forward-year)
1931   (define-key calendar-mode-map "\C-a"  'calendar-beginning-of-week)
1932   (define-key calendar-mode-map "\C-e"  'calendar-end-of-week)
1933   (define-key calendar-mode-map "\ea"   'calendar-beginning-of-month)
1934   (define-key calendar-mode-map "\ee"   'calendar-end-of-month)
1935   (define-key calendar-mode-map "\e<"   'calendar-beginning-of-year)
1936   (define-key calendar-mode-map "\e>"   'calendar-end-of-year)
1937   (define-key calendar-mode-map "\C-@"  'calendar-set-mark)
1938   ;; Many people are used to typing C-SPC and getting C-@.
1939   (define-key calendar-mode-map [?\C- ] 'calendar-set-mark)
1940   (define-key calendar-mode-map "\C-x\C-x" 'calendar-exchange-point-and-mark)
1941   (define-key calendar-mode-map "\e=" 'calendar-count-days-region)
1942   (define-key calendar-mode-map "gd"  'calendar-goto-date)
1943   (define-key calendar-mode-map "gj"  'calendar-goto-julian-date)
1944   (define-key calendar-mode-map "ga"  'calendar-goto-astro-day-number)
1945   (define-key calendar-mode-map "gh"  'calendar-goto-hebrew-date)
1946   (define-key calendar-mode-map "gi"  'calendar-goto-islamic-date)
1947   (define-key calendar-mode-map "gC"  'calendar-goto-chinese-date)
1948   (define-key calendar-mode-map "gk"  'calendar-goto-coptic-date)
1949   (define-key calendar-mode-map "ge"  'calendar-goto-ethiopic-date)
1950   (define-key calendar-mode-map "gp"  'calendar-goto-persian-date)
1951   (define-key calendar-mode-map "gc"  'calendar-goto-iso-date)
1952   (define-key calendar-mode-map "gf"  'calendar-goto-french-date)
1953   (define-key calendar-mode-map "gml"  'calendar-goto-mayan-long-count-date)
1954   (define-key calendar-mode-map "gmpc" 'calendar-previous-calendar-round-date)
1955   (define-key calendar-mode-map "gmnc" 'calendar-next-calendar-round-date)
1956   (define-key calendar-mode-map "gmph" 'calendar-previous-haab-date)
1957   (define-key calendar-mode-map "gmnh" 'calendar-next-haab-date)
1958   (define-key calendar-mode-map "gmpt" 'calendar-previous-tzolkin-date)
1959   (define-key calendar-mode-map "gmnt" 'calendar-next-tzolkin-date)
1960   (define-key calendar-mode-map "Aa"   'appt-add)
1961   (define-key calendar-mode-map "Ad"   'appt-delete)
1962   (define-key calendar-mode-map "S"   'calendar-sunrise-sunset)
1963   (define-key calendar-mode-map "M"   'calendar-phases-of-moon)
1964   (define-key calendar-mode-map " "   'scroll-other-window)
1965   (define-key calendar-mode-map "\C-c\C-l" 'redraw-calendar)
1966   (define-key calendar-mode-map "."   'calendar-goto-today)
1967   (define-key calendar-mode-map "o"   'calendar-other-month)
1968   (define-key calendar-mode-map "q"   'exit-calendar)
1969   (define-key calendar-mode-map "a"   'list-calendar-holidays)
1970   (define-key calendar-mode-map "h"   'calendar-cursor-holidays)
1971   (define-key calendar-mode-map "x"   'mark-calendar-holidays)
1972   (define-key calendar-mode-map "u"   'calendar-unmark)
1973   (define-key calendar-mode-map "m"   'mark-diary-entries)
1974   (define-key calendar-mode-map "d"   'view-diary-entries)
1975   (define-key calendar-mode-map "D"   'view-other-diary-entries)
1976   (define-key calendar-mode-map "s"   'show-all-diary-entries)
1977   (define-key calendar-mode-map "pd"  'calendar-print-day-of-year)
1978   (define-key calendar-mode-map "pC"  'calendar-print-chinese-date)
1979   (define-key calendar-mode-map "pk"  'calendar-print-coptic-date)
1980   (define-key calendar-mode-map "pe"  'calendar-print-ethiopic-date)
1981   (define-key calendar-mode-map "pp"  'calendar-print-persian-date)
1982   (define-key calendar-mode-map "pc"  'calendar-print-iso-date)
1983   (define-key calendar-mode-map "pj"  'calendar-print-julian-date)
1984   (define-key calendar-mode-map "pa"  'calendar-print-astro-day-number)
1985   (define-key calendar-mode-map "ph"  'calendar-print-hebrew-date)
1986   (define-key calendar-mode-map "pi"  'calendar-print-islamic-date)
1987   (define-key calendar-mode-map "pf"  'calendar-print-french-date)
1988   (define-key calendar-mode-map "pm"  'calendar-print-mayan-date)
1989   (define-key calendar-mode-map "po"  'calendar-print-other-dates)
1990   (define-key calendar-mode-map "id"  'insert-diary-entry)
1991   (define-key calendar-mode-map "iw"  'insert-weekly-diary-entry)
1992   (define-key calendar-mode-map "im"  'insert-monthly-diary-entry)
1993   (define-key calendar-mode-map "iy"  'insert-yearly-diary-entry)
1994   (define-key calendar-mode-map "ia"  'insert-anniversary-diary-entry)
1995   (define-key calendar-mode-map "ib"  'insert-block-diary-entry)
1996   (define-key calendar-mode-map "ic"  'insert-cyclic-diary-entry)
1997   (define-key calendar-mode-map "ihd" 'insert-hebrew-diary-entry)
1998   (define-key calendar-mode-map "ihm" 'insert-monthly-hebrew-diary-entry)
1999   (define-key calendar-mode-map "ihy" 'insert-yearly-hebrew-diary-entry)
2000   (define-key calendar-mode-map "iid" 'insert-islamic-diary-entry)
2001   (define-key calendar-mode-map "iim" 'insert-monthly-islamic-diary-entry)
2002   (define-key calendar-mode-map "iiy" 'insert-yearly-islamic-diary-entry)
2003   (define-key calendar-mode-map "?"   'calendar-goto-info-node)
2004   (define-key calendar-mode-map "tm" 'cal-tex-cursor-month)
2005   (define-key calendar-mode-map "tM" 'cal-tex-cursor-month-landscape)
2006   (define-key calendar-mode-map "td" 'cal-tex-cursor-day)
2007   (define-key calendar-mode-map "tw1" 'cal-tex-cursor-week)
2008   (define-key calendar-mode-map "tw2" 'cal-tex-cursor-week2)
2009   (define-key calendar-mode-map "tw3" 'cal-tex-cursor-week-iso)
2010   (define-key calendar-mode-map "tw4" 'cal-tex-cursor-week-monday)
2011   (define-key calendar-mode-map "tfd" 'cal-tex-cursor-filofax-daily)
2012   (define-key calendar-mode-map "tfw" 'cal-tex-cursor-filofax-2week)
2013   (define-key calendar-mode-map "tfW" 'cal-tex-cursor-filofax-week)
2014   (define-key calendar-mode-map "tfy" 'cal-tex-cursor-filofax-year)
2015   (define-key calendar-mode-map "ty" 'cal-tex-cursor-year)
2016   (define-key calendar-mode-map "tY" 'cal-tex-cursor-year-landscape))
2017
2018 (defun describe-calendar-mode ()
2019   "Create a help buffer with a brief description of the calendar-mode."
2020   (interactive)
2021   (with-output-to-temp-buffer "*Help*"
2022     (princ
2023      (format
2024       "Calendar Mode:\nFor a complete description, type %s\n%s\n"
2025       (substitute-command-keys
2026        "\\<calendar-mode-map>\\[describe-mode] from within the calendar")
2027       (substitute-command-keys "\\{calendar-mode-map}")))
2028     (save-excursion
2029       (set-buffer standard-output)
2030       (help-mode))
2031     (print-help-return-message)))
2032
2033 ;; Calendar mode is suitable only for specially formatted data.
2034 (put 'calendar-mode 'mode-class 'special)
2035
2036 (defvar calendar-mode-line-format
2037   (list
2038    (propertize (substitute-command-keys
2039                 "\\<calendar-mode-map>\\[scroll-calendar-left]")
2040                'help-echo "mouse-2: scroll left"
2041                'keymap (make-mode-line-mouse2-map #'scroll-calendar-left))
2042    "Calendar"
2043    (concat
2044     (propertize
2045      (substitute-command-keys
2046       "\\<calendar-mode-map>\\[calendar-goto-info-node] info")
2047      'help-echo "mouse-2: read Info on Calendar"
2048      'keymap (make-mode-line-mouse2-map #'calendar-goto-info-node))
2049     "/"
2050     (propertize
2051      (substitute-command-keys
2052      "\\<calendar-mode-map>\\[calendar-other-month] other")
2053      'help-echo "mouse-2: choose another month"
2054      'keymap (make-mode-line-mouse2-map (lambda ()
2055                                           (interactive)
2056                                           (call-interactively
2057                                            'calendar-other-month))))
2058     "/"
2059     (propertize
2060      (substitute-command-keys
2061      "\\<calendar-mode-map>\\[calendar-goto-today] today")
2062      'help-echo "mouse-2: go to today's date"
2063      'keymap (make-mode-line-mouse2-map #'calendar-goto-today)))
2064    '(calendar-date-string (calendar-current-date) t)
2065    (propertize (substitute-command-keys
2066                 "\\<calendar-mode-map>\\[scroll-calendar-right]")
2067                'help-echo "mouse-2: scroll right"
2068                'keymap (make-mode-line-mouse2-map #'scroll-calendar-right)))
2069   "The mode line of the calendar buffer.")
2070
2071 (defun calendar-goto-info-node ()
2072   "Go to the info node for the calendar."
2073   (interactive)
2074   (require 'info)
2075   (let ((where (save-window-excursion
2076                  (Info-find-emacs-command-nodes 'calendar))))
2077     (if (not where)
2078         (error "Couldn't find documentation for the calendar.")
2079       (let (same-window-buffer-names)
2080         (info))
2081       (Info-find-node (car (car where)) (car (cdr (car where)))))))
2082
2083 (defun calendar-mode ()
2084   "A major mode for the calendar window.
2085
2086 For a complete description, type \
2087 \\<calendar-mode-map>\\[calendar-goto-info-node] from within the calendar.
2088
2089 \\<calendar-mode-map>\\{calendar-mode-map}"
2090
2091   (kill-all-local-variables)
2092   (setq major-mode 'calendar-mode)
2093   (setq mode-name "Calendar")
2094   (use-local-map calendar-mode-map)
2095   (setq buffer-read-only t)
2096   (setq indent-tabs-mode nil)
2097   (update-calendar-mode-line)
2098   (if window-system
2099       (progn
2100         (make-local-hook 'activate-menubar-hook)
2101         (add-hook 'activate-menubar-hook 'cal-menu-update nil t)))
2102   (make-local-variable 'calendar-mark-ring)
2103   (make-local-variable 'displayed-month);;  Month in middle of window.
2104   (make-local-variable 'displayed-year));;  Year in middle of window.
2105
2106 (defun calendar-string-spread (strings char length)
2107   "Concatenate list of STRINGS separated with copies of CHAR to fill LENGTH.
2108 The effect is like mapconcat but the separating pieces are as balanced as
2109 possible.  Each item of STRINGS is evaluated before concatenation so it can
2110 actually be an expression that evaluates to a string.  If LENGTH is too short,
2111 the STRINGS are just concatenated and the result truncated."
2112 ;; The algorithm is based on equation (3.25) on page 85 of Concrete
2113 ;; Mathematics by Ronald L. Graham, Donald E. Knuth, and Oren Patashnik,
2114 ;; Addison-Wesley, Reading, MA, 1989
2115   (let* ((strings (mapcar 'eval
2116                           (if (< (length strings) 2)
2117                               (append (list "") strings (list ""))
2118                             strings)))
2119          (n (- length (length (apply 'concat strings))))
2120          (m (1- (length strings)))
2121          (s (car strings))
2122          (strings (cdr strings))
2123          (i 0))
2124     (while strings
2125       (setq s (concat s
2126                       (make-string (max 0 (/ (+ n i) m)) char)
2127                       (car strings)))
2128       (setq i (1+ i))
2129       (setq strings (cdr strings)))
2130     (substring s 0 length)))
2131
2132 (defun update-calendar-mode-line ()
2133   "Update the calendar mode line with the current date and date style."
2134   (if (bufferp (get-buffer calendar-buffer))
2135       (save-excursion
2136         (set-buffer calendar-buffer)
2137         (setq mode-line-format
2138               (calendar-string-spread
2139                calendar-mode-line-format ?  (frame-width))))))
2140
2141 (defun calendar-window-list ()
2142   "List of all calendar-related windows."
2143   (let ((calendar-buffers (calendar-buffer-list))
2144         list)
2145     (walk-windows (lambda (w)
2146                     (if (memq (window-buffer w) calendar-buffers)
2147                         (setq list (cons w list))))
2148                   nil t)
2149     list))
2150
2151 (defun calendar-buffer-list ()
2152   "List of all calendar-related buffers."
2153   (let* ((diary-buffer (get-file-buffer diary-file))
2154          (buffers (list "*Yahrzeits*" lunar-phases-buffer holiday-buffer
2155                         fancy-diary-buffer diary-buffer calendar-buffer
2156                         other-calendars-buffer))
2157          (buffer-list nil)
2158          b)
2159     (while buffers
2160       (setq b (car buffers))
2161       (setq b (cond ((stringp b) (get-buffer b))
2162                     ((bufferp b) b)
2163                     (t nil)))
2164       (if b (setq buffer-list (cons b buffer-list)))
2165       (setq buffers (cdr buffers)))
2166     buffer-list))
2167
2168 (defun exit-calendar ()
2169   "Get out of the calendar window and hide it and related buffers."
2170   (interactive)
2171   (let* ((diary-buffer (get-file-buffer diary-file)))
2172     (if (or (not diary-buffer)
2173             (not (buffer-modified-p diary-buffer))
2174             (yes-or-no-p
2175              "Diary modified; do you really want to exit the calendar? "))
2176       ;; Need to do this multiple times because one time can replace some
2177       ;; calendar-related buffers with other calendar-related buffers
2178       (mapcar (lambda (x)
2179                 (mapcar 'calendar-hide-window (calendar-window-list)))
2180               (calendar-window-list)))))
2181
2182 (defun calendar-hide-window (window)
2183   "Hide WINDOW if it is calendar-related."
2184   (let ((buffer (if (window-live-p window) (window-buffer window))))
2185     (if (memq buffer (calendar-buffer-list))
2186         (cond
2187          ((and window-system
2188                (eq 'icon (cdr (assoc 'visibility
2189                                      (frame-parameters
2190                                       (window-frame window))))))
2191           nil)
2192          ((and window-system (window-dedicated-p window))
2193           (if calendar-remove-frame-by-deleting
2194               (delete-frame (window-frame window))
2195               (iconify-frame (window-frame window))))
2196          ((not (and (select-window window) (one-window-p window)))
2197           (delete-window window))
2198          (t (set-buffer buffer)
2199             (bury-buffer))))))
2200
2201 (defun calendar-current-date ()
2202   "Return the current date in a list (month day year)."
2203   (let ((now (decode-time)))
2204     (list (nth 4 now) (nth 3 now) (nth 5 now))))
2205
2206 (defun calendar-cursor-to-date (&optional error)
2207   "Return a list (month day year) of current cursor position.
2208 If cursor is not on a specific date, signals an error if optional parameter
2209 ERROR is t, otherwise just returns nil."
2210   (let* ((segment (/ (current-column) 25))
2211          (month (% (+ displayed-month segment -1) 12))
2212          (month (if (= 0 month) 12 month))
2213          (year
2214           (cond
2215            ((and (=  12 month) (= segment 0)) (1- displayed-year))
2216            ((and (=   1 month) (= segment 2)) (1+ displayed-year))
2217            (t displayed-year))))
2218     (if (and (looking-at "[ 0-9]?[0-9][^0-9]")
2219              (< 2 (count-lines (point-min) (point))))
2220         (save-excursion
2221           (if (not (looking-at " "))
2222                    (re-search-backward "[^0-9]"))
2223           (list month
2224                 (string-to-int (buffer-substring (1+ (point)) (+ 4 (point))))
2225                 year))
2226       (if (looking-at "\\*")
2227           (save-excursion
2228             (re-search-backward "[^*]")
2229             (if (looking-at ".\\*\\*")
2230                 (list month calendar-starred-day year)
2231               (if error (error "Not on a date!"))))
2232         (if error (error "Not on a date!"))))))
2233
2234 ;; The following version of calendar-gregorian-from-absolute is preferred for
2235 ;; reasons of clarity, BUT it's much slower than the version that follows it.
2236
2237 ;;(defun calendar-gregorian-from-absolute (date)
2238 ;;  "Compute the list (month day year) corresponding to the absolute DATE.
2239 ;;The absolute date is the number of days elapsed since the (imaginary)
2240 ;;Gregorian date Sunday, December 31, 1 BC."
2241 ;;  (let* ((approx (/ date 366));; Approximation from below.
2242 ;;         (year                ;; Search forward from the approximation.
2243 ;;          (+ approx
2244 ;;             (calendar-sum y approx
2245 ;;                 (>= date (calendar-absolute-from-gregorian (list 1 1 (1+ y))))
2246 ;;                  1)))
2247 ;;         (month         ;; Search forward from January.
2248 ;;          (1+ (calendar-sum m 1
2249 ;;                   (> date
2250 ;;                      (calendar-absolute-from-gregorian
2251 ;;                       (list m (calendar-last-day-of-month m year) year)))
2252 ;;                   1)))
2253 ;;         (day           ;; Calculate the day by subtraction.
2254 ;;          (- date
2255 ;;             (1- (calendar-absolute-from-gregorian (list month 1 year))))))
2256 ;;    (list month day year)))
2257
2258 (defun calendar-gregorian-from-absolute (date)
2259   "Compute the list (month day year) corresponding to the absolute DATE.
2260 The absolute date is the number of days elapsed since the (imaginary)
2261 Gregorian date Sunday, December 31, 1 BC."
2262 ;; See the footnote on page 384 of ``Calendrical Calculations, Part II:
2263 ;; Three Historical Calendars'' by E. M. Reingold,  N. Dershowitz, and S. M.
2264 ;; Clamen, Software--Practice and Experience, Volume 23, Number 4
2265 ;; (April, 1993), pages 383-404 for an explanation.
2266   (let* ((d0 (1- date))
2267          (n400 (/ d0 146097))
2268          (d1 (% d0 146097))
2269          (n100 (/ d1 36524))
2270          (d2 (% d1 36524))
2271          (n4 (/ d2 1461))
2272          (d3 (% d2 1461))
2273          (n1 (/ d3 365))
2274          (day (1+ (% d3 365)))
2275          (year (+ (* 400 n400) (* 100 n100) (* n4 4) n1)))
2276     (if (or (= n100 4) (= n1 4))
2277         (list 12 31 year)
2278       (let ((year (1+ year))
2279             (month 1))
2280         (while (let ((mdays (calendar-last-day-of-month month year)))
2281                  (and (< mdays day)
2282                       (setq day (- day mdays))))
2283           (setq month (1+ month)))
2284         (list month day year)))))
2285
2286 (defun calendar-other-month (month year)
2287   "Display a three-month calendar centered around MONTH and YEAR."
2288   (interactive (calendar-read-date 'noday))
2289   (if (and (= month displayed-month)
2290            (= year displayed-year))
2291       nil
2292     (let ((old-date (calendar-cursor-to-date))
2293           (today (calendar-current-date)))
2294       (generate-calendar-window month year)
2295       (calendar-cursor-to-visible-date
2296        (cond
2297         ((calendar-date-is-visible-p old-date) old-date)
2298         ((calendar-date-is-visible-p today) today)
2299         (t (list month 1 year)))))))
2300
2301 (defun calendar-set-mark (arg)
2302   "Mark the date under the cursor, or jump to marked date.
2303 With no prefix argument, push current date onto marked date ring.
2304 With argument, jump to mark, pop it, and put point at end of ring."
2305   (interactive "P")
2306   (let ((date (calendar-cursor-to-date t)))
2307     (if (null arg)
2308         (progn
2309           (setq calendar-mark-ring (cons date calendar-mark-ring))
2310           ;; Since the top of the mark ring is the marked date in the
2311           ;; calendar, the mark ring in the calendar is one longer than
2312           ;; in other buffers to get the same effect.
2313           (if (> (length calendar-mark-ring) (1+ mark-ring-max))
2314               (setcdr (nthcdr mark-ring-max calendar-mark-ring) nil))
2315           (message "Mark set"))
2316       (if (null calendar-mark-ring)
2317           (error "No mark set in this buffer")
2318         (calendar-goto-date (car calendar-mark-ring))
2319         (setq calendar-mark-ring
2320               (cdr (nconc calendar-mark-ring (list date))))))))
2321
2322 (defun calendar-exchange-point-and-mark ()
2323   "Exchange the current cursor position with the marked date."
2324   (interactive)
2325   (let ((mark (car calendar-mark-ring))
2326         (date (calendar-cursor-to-date t)))
2327     (if (null mark)
2328         (error "No mark set in this buffer")
2329       (setq calendar-mark-ring (cons date (cdr calendar-mark-ring)))
2330       (calendar-goto-date mark))))
2331
2332 (defun calendar-count-days-region ()
2333   "Count the number of days (inclusive) between point and the mark."
2334   (interactive)
2335   (let* ((days (- (calendar-absolute-from-gregorian
2336                    (calendar-cursor-to-date t))
2337                   (calendar-absolute-from-gregorian
2338                    (or (car calendar-mark-ring)
2339                        (error "No mark set in this buffer")))))
2340          (days (1+ (if (> days 0) days (- days)))))
2341     (message "Region has %d day%s (inclusive)"
2342              days (if (> days 1) "s" ""))))
2343
2344 (defun calendar-not-implemented ()
2345   "Not implemented."
2346   (interactive)
2347   (error "%s not available in the calendar"
2348          (global-key-binding (this-command-keys))))
2349
2350 (defun calendar-read (prompt acceptable &optional initial-contents)
2351   "Return an object read from the minibuffer.
2352 Prompt with the string PROMPT and use the function ACCEPTABLE to decide if
2353 entered item is acceptable.  If non-nil, optional third arg INITIAL-CONTENTS
2354 is a string to insert in the minibuffer before reading."
2355   (let ((value (read-minibuffer prompt initial-contents)))
2356     (while (not (funcall acceptable value))
2357       (setq value (read-minibuffer prompt initial-contents)))
2358     value))
2359
2360 (defun calendar-read-date (&optional noday)
2361   "Prompt for Gregorian date.  Return a list (month day year).
2362 If optional NODAY is t, does not ask for day, but just returns
2363 \(month nil year); if NODAY is any other non-nil value the value returned is
2364 \(month year)"
2365   (let* ((year (calendar-read
2366                 "Year (>0): "
2367                 (lambda (x) (> x 0))
2368                 (int-to-string (extract-calendar-year
2369                                 (calendar-current-date)))))
2370          (month-array calendar-month-name-array)
2371          (completion-ignore-case t)
2372          (month (cdr (assoc-ignore-case
2373                        (completing-read
2374                         "Month name: "
2375                         (mapcar 'list (append month-array nil))
2376                         nil t)
2377                       (calendar-make-alist month-array 1))))
2378          (last (calendar-last-day-of-month month year)))
2379     (if noday
2380         (if (eq noday t)
2381             (list month nil year)
2382           (list month year))
2383       (list month
2384             (calendar-read (format "Day (1-%d): " last)
2385                            (lambda (x) (and (< 0 x) (<= x last))))
2386             year))))
2387
2388 (defun calendar-interval (mon1 yr1 mon2 yr2)
2389   "The number of months difference between MON1, YR1 and MON2, YR2."
2390   (+ (* 12 (- yr2 yr1))
2391      (- mon2 mon1)))
2392
2393 (defun calendar-day-name (date &optional width absolute)
2394   "Return a string with the name of the day of the week of DATE.
2395 If WIDTH is non-nil, return just the first WIDTH characters of the name.
2396 If ABSOLUTE is non-nil, then DATE is actually the day-of-the-week
2397 rather than a date."
2398   (let ((string (aref calendar-day-name-array
2399                       (if absolute date (calendar-day-of-week date)))))
2400     (cond ((null width) string)
2401           (enable-multibyte-characters (truncate-string-to-width string width))
2402           (t (substring string 0 width)))))
2403
2404 (defvar calendar-day-name-array
2405   ["Sunday" "Monday" "Tuesday" "Wednesday" "Thursday" "Friday" "Saturday"]
2406   "Array of capitalized strings giving, in order, the day names.")
2407
2408 (defvar calendar-month-name-array
2409   ["January" "February" "March"     "April"   "May"      "June"
2410    "July"    "August"   "September" "October" "November" "December"]
2411   "Array of capitalized strings giving, in order, the month names.")
2412
2413 (defun calendar-make-alist (sequence &optional start-index filter)
2414   "Make an assoc list corresponding to SEQUENCE.
2415 Start at index 1, unless optional START-INDEX is provided.
2416 If FILTER is provided, apply it to each item in the list."
2417   (let ((index (if start-index (1- start-index) 0)))
2418     (mapcar
2419      (lambda (x)
2420         (setq index (1+ index))
2421         (cons (if filter (funcall filter x) x)
2422               index))
2423      (append sequence nil))))
2424
2425 (defun calendar-month-name (month &optional width)
2426   "The name of MONTH.
2427 If WIDTH is non-nil, return just the first WIDTH characters of the name."
2428   (let ((string (aref calendar-month-name-array (1- month))))
2429     (if width
2430         (let ((i 0) (result "") (pos 0))
2431           (while (< i width)
2432             (let ((chartext (char-to-string (aref string pos))))
2433               (setq pos (+ pos (length chartext)))
2434               (setq result (concat result chartext)))
2435             (setq i (1+ i)))
2436           result)
2437       string)))
2438
2439 (defun calendar-day-of-week (date)
2440   "Return the day-of-the-week index of DATE, 0 for Sunday, 1 for Monday, etc."
2441   (% (calendar-absolute-from-gregorian date) 7))
2442
2443 (defun calendar-unmark ()
2444   "Delete all diary/holiday marks/highlighting from the calendar."
2445   (interactive)
2446   (setq mark-holidays-in-calendar nil)
2447   (setq mark-diary-entries-in-calendar nil)
2448   (redraw-calendar))
2449
2450 (defun calendar-date-is-visible-p (date)
2451   "Return t if DATE is legal and is visible in the calendar window."
2452   (let ((gap (calendar-interval
2453               displayed-month displayed-year
2454               (extract-calendar-month date) (extract-calendar-year date))))
2455     (and (calendar-date-is-legal-p date) (> 2 gap) (< -2 gap))))
2456
2457 (defun calendar-date-is-legal-p (date)
2458   "Return t if DATE is a legal date."
2459   (let ((month (extract-calendar-month date))
2460         (day (extract-calendar-day date))
2461         (year (extract-calendar-year date)))
2462     (and (<= 1 month) (<= month 12)
2463          (<= 1 day) (<= day (calendar-last-day-of-month month year))
2464          (<= 1 year))))
2465
2466 (defun calendar-date-equal (date1 date2)
2467   "Return t if the DATE1 and DATE2 are the same."
2468   (and
2469    (= (extract-calendar-month date1) (extract-calendar-month date2))
2470    (= (extract-calendar-day date1) (extract-calendar-day date2))
2471    (= (extract-calendar-year date1) (extract-calendar-year date2))))
2472
2473 (defun mark-visible-calendar-date (date &optional mark)
2474   "Mark DATE in the calendar window with MARK.
2475 MARK is either a single-character string or a face.
2476 MARK defaults to diary-entry-marker."
2477   (if (calendar-date-is-legal-p date)
2478       (save-excursion
2479         (set-buffer calendar-buffer)
2480         (calendar-cursor-to-visible-date date)
2481         (let ((mark (or mark diary-entry-marker)))
2482           (if (stringp mark)
2483               (let ((buffer-read-only nil))
2484                 (forward-char 1)
2485                 (delete-char 1)
2486                 (insert mark)
2487                 (forward-char -2))
2488             (overlay-put
2489              (make-overlay (1- (point)) (1+ (point))) 'face mark))))))
2490
2491 (defun calendar-star-date ()
2492   "Replace the date under the cursor in the calendar window with asterisks.
2493 This function can be used with the `today-visible-calendar-hook' run after the
2494 calendar window has been prepared."
2495   (let ((inhibit-read-only t))
2496     (make-local-variable 'calendar-starred-day)
2497     (forward-char 1)
2498     (setq calendar-starred-day
2499           (string-to-int
2500            (buffer-substring (point) (- (point) 2))))
2501     (delete-char -2)
2502     (insert "**")
2503     (backward-char 1)
2504     (set-buffer-modified-p nil)))
2505
2506 (defun calendar-mark-today ()
2507   "Mark the date under the cursor in the calendar window.
2508 The date is marked with calendar-today-marker.  This function can be used with
2509 the `today-visible-calendar-hook' run after the calendar window has been
2510 prepared."
2511   (mark-visible-calendar-date
2512    (calendar-cursor-to-date)
2513    calendar-today-marker))
2514
2515 (defun calendar-date-compare (date1 date2)
2516   "Return t if DATE1 is before DATE2, nil otherwise.
2517 The actual dates are in the car of DATE1 and DATE2."
2518   (< (calendar-absolute-from-gregorian (car date1))
2519      (calendar-absolute-from-gregorian (car date2))))
2520
2521 (defun calendar-date-string (date &optional abbreviate nodayname)
2522   "A string form of DATE, driven by the variable `calendar-date-display-form'.
2523 An optional parameter ABBREVIATE, when t, causes the month and day names to be
2524 abbreviated to three characters.  An optional parameter NODAYNAME, when t,
2525 omits the name of the day of the week."
2526   (let* ((dayname
2527           (if nodayname
2528               nil
2529             (if abbreviate
2530                 (calendar-day-name date 3)
2531               (calendar-day-name date))))
2532          (month (extract-calendar-month date))
2533          (monthname
2534           (if abbreviate
2535               (calendar-month-name month 3)
2536             (calendar-month-name month)))
2537          (day (int-to-string (extract-calendar-day date)))
2538          (month (int-to-string month))
2539          (year (int-to-string (extract-calendar-year date))))
2540     (mapconcat 'eval calendar-date-display-form "")))
2541
2542 (defun calendar-dayname-on-or-before (dayname date)
2543   "Return the absolute date of the DAYNAME on or before absolute DATE.
2544 DAYNAME=0 means Sunday, DAYNAME=1 means Monday, and so on.
2545
2546 Note: Applying this function to d+6 gives us the DAYNAME on or after an
2547 absolute day d.  Similarly, applying it to d+3 gives the DAYNAME nearest to
2548 absolute date d, applying it to d-1 gives the DAYNAME previous to absolute
2549 date d, and applying it to d+7 gives the DAYNAME following absolute date d."
2550   (- date (% (- date dayname) 7)))
2551
2552 (defun calendar-nth-named-absday (n dayname month year &optional day)
2553   "The absolute date of Nth DAYNAME in MONTH, YEAR before/after optional DAY.
2554 A DAYNAME of 0 means Sunday, 1 means Monday, and so on.  If N<0,
2555 return the Nth DAYNAME before MONTH DAY, YEAR (inclusive).
2556 If N>0, return the Nth DAYNAME after MONTH DAY, YEAR (inclusive).
2557
2558 If DAY is omitted, it defaults to 1 if N>0, and MONTH's last day otherwise."
2559   (if (> n 0)
2560       (+ (* 7 (1- n))
2561          (calendar-dayname-on-or-before
2562           dayname
2563           (+ 6 (calendar-absolute-from-gregorian
2564                 (list month (or day 1) year)))))
2565     (+ (* 7 (1+ n))
2566        (calendar-dayname-on-or-before
2567         dayname
2568         (calendar-absolute-from-gregorian
2569          (list month
2570                (or day (calendar-last-day-of-month month year))
2571                year))))))
2572
2573 (defun calendar-nth-named-day (n dayname month year &optional day)
2574   "The date of Nth DAYNAME in MONTH, YEAR before/after optional DAY.
2575 A DAYNAME of 0 means Sunday, 1 means Monday, and so on.  If N<0,
2576 return the Nth DAYNAME before MONTH DAY, YEAR (inclusive).
2577 If N>0, return the Nth DAYNAME after MONTH DAY, YEAR (inclusive).
2578
2579 If DAY is omitted, it defaults to 1 if N>0, and MONTH's last day otherwise."
2580   (calendar-gregorian-from-absolute
2581    (calendar-nth-named-absday n dayname month year day)))
2582
2583 (defun calendar-day-of-year-string (&optional date)
2584   "String of day number of year of Gregorian DATE.
2585 Defaults to today's date if DATE is not given."
2586   (let* ((d (or date (calendar-current-date)))
2587          (year (extract-calendar-year d))
2588          (day (calendar-day-number d))
2589          (days-remaining (- (calendar-day-number (list 12 31 year)) day)))
2590     (format "Day %d of %d; %d day%s remaining in the year"
2591             day year days-remaining (if (= days-remaining 1) "" "s"))))
2592
2593 (defun calendar-print-other-dates ()
2594   "Show dates on other calendars for date under the cursor."
2595   (interactive)
2596   (let* ((date (calendar-cursor-to-date t)))
2597     (save-excursion
2598       (set-buffer (get-buffer-create other-calendars-buffer))
2599       (setq buffer-read-only nil)
2600       (calendar-set-mode-line
2601        (concat (calendar-date-string date) " (Gregorian)"))
2602       (erase-buffer)
2603       (insert
2604        (mapconcat 'identity
2605                   (list (calendar-day-of-year-string date)
2606                         (format "ISO date: %s" (calendar-iso-date-string date))
2607                         (format "Julian date: %s"
2608                                 (calendar-julian-date-string date))
2609                         (format
2610                          "Astronomical (Julian) day number (at noon UTC): %s.0"
2611                          (calendar-astro-date-string date))
2612                         (format "Fixed (RD) date: %s"
2613                                 (calendar-absolute-from-gregorian date))
2614                         (format "Hebrew date (before sunset): %s"
2615                                 (calendar-hebrew-date-string date))
2616                         (format "Persian date: %s"
2617                                 (calendar-persian-date-string date))
2618                         (let ((i (calendar-islamic-date-string date)))
2619                           (if (not (string-equal i ""))
2620                               (format "Islamic date (before sunset): %s" i)))
2621                         (format "Chinese date: %s"
2622                                 (calendar-chinese-date-string date))
2623                         (let ((c (calendar-coptic-date-string date)))
2624                           (if (not (string-equal c ""))
2625                               (format "Coptic date: %s" c)))
2626                         (let ((e (calendar-ethiopic-date-string date)))
2627                           (if (not (string-equal e ""))
2628                               (format "Ethiopic date: %s" e)))
2629                         (let ((f (calendar-french-date-string date)))
2630                           (if (not (string-equal f ""))
2631                               (format "French Revolutionary date: %s" f)))
2632                         (format "Mayan date: %s"
2633                                 (calendar-mayan-date-string date)))
2634                   "\n"))
2635       (goto-char (point-min))
2636       (set-buffer-modified-p nil)
2637       (setq buffer-read-only t)
2638       (display-buffer other-calendars-buffer))))
2639
2640 (defun calendar-print-day-of-year ()
2641   "Show day number in year/days remaining in year for date under the cursor."
2642   (interactive)
2643   (message (calendar-day-of-year-string (calendar-cursor-to-date t))))
2644
2645 (defun calendar-set-mode-line (str)
2646   "Set mode line to STR, centered, surrounded by dashes."
2647   (setq mode-line-format
2648         (calendar-string-spread (list str) ?- (frame-width))))
2649
2650 (defun calendar-mod (m n)
2651   "Non-negative remainder of M/N with N instead of 0."
2652   (1+ (mod (1- m) n)))
2653
2654 (run-hooks 'calendar-load-hook)
2655
2656 (provide 'calendar)
2657
2658 ;;; Local variables:
2659 ;;; byte-compile-dynamic: t
2660 ;;; End:
2661
2662 ;;; calendar.el ends here