This is ../info/emacs, produced by makeinfo version 4.0 from emacs.texi.

   This is the thirteenth edition of the `GNU Emacs Manual', updated
for Emacs version 20.7.

INFO-DIR-SECTION Editors
START-INFO-DIR-ENTRY
* Emacs: (emacs).	The extensible self-documenting text editor.
END-INFO-DIR-ENTRY

   Published by the Free Software Foundation 59 Temple Place, Suite 330
Boston, MA  02111-1307 USA

   Copyright (C) 1985, 1986, 1987, 1993, 1994, 1995, 1996, 1997, 1998,
1999    Free Software Foundation, Inc.

   Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.

   Permission is granted to copy and distribute modified versions of
this manual under the conditions for verbatim copying, provided also
that the sections entitled "The GNU Manifesto", "Distribution" and "GNU
General Public License" are included exactly as in the original, and
provided that the entire resulting derived work is distributed under the
terms of a permission notice identical to this one.

   Permission is granted to copy and distribute translations of this
manual into another language, under the above conditions for modified
versions, except that the sections entitled "The GNU Manifesto",
"Distribution" and "GNU General Public License" may be included in a
translation approved by the Free Software Foundation instead of in the
original English.


File: emacs,  Node: Dired Updating,  Next: Dired and Find,  Prev: Hiding Subdirectories,  Up: Dired

Updating the Dired Buffer
=========================

   This section describes commands to update the Dired buffer to reflect
outside (non-Dired) changes in the directories and files, and to delete
part of the Dired buffer.

`g'
     Update the entire contents of the Dired buffer (`revert-buffer').

`l'
     Update the specified files (`dired-do-redisplay').

`k'
     Delete the specified _file lines_--not the files, just the lines
     (`dired-do-kill-lines').

`s'
     Toggle between alphabetical order and date/time order
     (`dired-sort-toggle-or-edit').

`C-u s SWITCHES <RET>'
     Refresh the Dired buffer using SWITCHES as
     `dired-listing-switches'.

   Type `g' (`revert-buffer') to update the contents of the Dired
buffer, based on changes in the files and directories listed.  This
preserves all marks except for those on files that have vanished.
Hidden subdirectories are updated but remain hidden.

   To update only some of the files, type `l' (`dired-do-redisplay').
This command applies to the next N files, or to the marked files if
any, or to the current file.  Updating them means reading their current
status from the file system and changing the buffer to reflect it
properly.

   If you use `l' on a subdirectory header line, it updates the
contents of the corresponding subdirectory.

   To delete the specified _file lines_--not the files, just the
lines--type `k' (`dired-do-kill-lines').  With a numeric argument N,
this command applies to the next N files; otherwise, it applies to the
marked files.

   If you kill the line for a file that is a directory, the directory's
contents are also deleted from the buffer.  Typing `C-u k' on the
header line for a subdirectory is another way to delete a subdirectory
from the Dired buffer.

   The `g' command brings back any individual lines that you have
killed in this way, but not subdirectories--you must use `i' to
reinsert each subdirectory.

   The files in a Dired buffers are normally listed in alphabetical
order by file names.  Alternatively Dired can sort them by date/time.
The Dired command `s' (`dired-sort-toggle-or-edit') switches between
these two sorting modes.  The mode line in a Dired buffer indicates
which way it is currently sorted--by name, or by date.

   `C-u s SWITCHES <RET>' lets you specify a new value for
`dired-listing-switches'.


File: emacs,  Node: Dired and Find,  Prev: Dired Updating,  Up: Dired

Dired and `find'
================

   You can select a set of files for display in a Dired buffer more
flexibly by using the `find' utility to choose the files.

   To search for files with names matching a wildcard pattern use `M-x
find-name-dired'.  It reads arguments DIRECTORY and PATTERN, and
chooses all the files in DIRECTORY or its subdirectories whose
individual names match PATTERN.

   The files thus chosen are displayed in a Dired buffer in which the
ordinary Dired commands are available.

   If you want to test the contents of files, rather than their names,
use `M-x find-grep-dired'.  This command reads two minibuffer
arguments, DIRECTORY and REGEXP; it chooses all the files in DIRECTORY
or its subdirectories that contain a match for REGEXP.  It works by
running the programs `find' and `grep'.  See also `M-x grep-find', in
*Note Compilation::.  Remember to write the regular expression for
`grep', not for Emacs.

   The most general command in this series is `M-x find-dired', which
lets you specify any condition that `find' can test.  It takes two
minibuffer arguments, DIRECTORY and FIND-ARGS; it runs `find' in
DIRECTORY, passing FIND-ARGS to tell `find' what condition to test.  To
use this command, you need to know how to use `find'.

   The format of listing produced by these commands is controlled by the
variable `find-ls-option', whose default value specifies using options
`-ld' for `ls'.  If your listings are corrupted, you may need to change
the value of this variable.


File: emacs,  Node: Calendar/Diary,  Next: Gnus,  Prev: Dired,  Up: Top

The Calendar and the Diary
**************************

   Emacs provides the functions of a desk calendar, with a diary of
planned or past events.  To enter the calendar, type `M-x calendar';
this displays a three-month calendar centered on the current month, with
point on the current date.  With a numeric argument, as in `C-u M-x
calendar', it prompts you for the month and year to be the center of the
three-month calendar.  The calendar uses its own buffer, whose major
mode is Calendar mode.

   `Mouse-2' in the calendar brings up a menu of operations on a
particular date; `C-Mouse-3' brings up a menu of commonly used calendar
features that are independent of any particular date.  To exit the
calendar, type `q'.  *Note Customizing the Calendar and Diary:
(elisp)Calendar, for customization information about the calendar and
diary.

* Menu:

* Calendar Motion::     Moving through the calendar; selecting a date.
* Scroll Calendar::     Bringing earlier or later months onto the screen.
* Counting Days::       How many days are there between two dates?
* General Calendar::    Exiting or recomputing the calendar.
* LaTeX Calendar::      Print a calendar using LaTeX.
* Holidays::            Displaying dates of holidays.
* Sunrise/Sunset::      Displaying local times of sunrise and sunset.
* Lunar Phases::        Displaying phases of the moon.
* Other Calendars::     Converting dates to other calendar systems.
* Diary::               Displaying events from your diary.
* Appointments::	Reminders when it's time to do something.
* Daylight Savings::    How to specify when daylight savings time is active.


File: emacs,  Node: Calendar Motion,  Next: Scroll Calendar,  Up: Calendar/Diary

Movement in the Calendar
========================

   Calendar mode lets you move through the calendar in logical units of
time such as days, weeks, months, and years.  If you move outside the
three months originally displayed, the calendar display "scrolls"
automatically through time to make the selected date visible.  Moving to
a date lets you view its holidays or diary entries, or convert it to
other calendars; moving longer time periods is also useful simply to
scroll the calendar.

* Menu:

* Calendar Unit Motion::      Moving by days, weeks, months, and years.
* Move to Beginning or End::  Moving to start/end of weeks, months, and years.
* Specified Dates::           Moving to the current date or another
                                specific date.


File: emacs,  Node: Calendar Unit Motion,  Next: Move to Beginning or End,  Up: Calendar Motion

Motion by Standard Lengths of Time
----------------------------------

   The commands for movement in the calendar buffer parallel the
commands for movement in text.  You can move forward and backward by
days, weeks, months, and years.

`C-f'
     Move point one day forward (`calendar-forward-day').

`C-b'
     Move point one day backward (`calendar-backward-day').

`C-n'
     Move point one week forward (`calendar-forward-week').

`C-p'
     Move point one week backward (`calendar-backward-week').

`M-}'
     Move point one month forward (`calendar-forward-month').

`M-{'
     Move point one month backward (`calendar-backward-month').

`C-x ]'
     Move point one year forward (`calendar-forward-year').

`C-x ['
     Move point one year backward (`calendar-backward-year').

   The day and week commands are natural analogues of the usual Emacs
commands for moving by characters and by lines.  Just as `C-n' usually
moves to the same column in the following line, in Calendar mode it
moves to the same day in the following week.  And `C-p' moves to the
same day in the previous week.

   The arrow keys are equivalent to `C-f', `C-b', `C-n' and `C-p', just
as they normally are in other modes.

   The commands for motion by months and years work like those for
weeks, but move a larger distance.  The month commands `M-}' and `M-{'
move forward or backward by an entire month's time.  The year commands
`C-x ]' and `C-x [' move forward or backward a whole year.

   The easiest way to remember these commands is to consider months and
years analogous to paragraphs and pages of text, respectively.  But the
commands themselves are not quite analogous.  The ordinary Emacs
paragraph commands move to the beginning or end of a paragraph, whereas
these month and year commands move by an entire month or an entire
year, which usually involves skipping across the end of a month or year.

   All these commands accept a numeric argument as a repeat count.  For
convenience, the digit keys and the minus sign specify numeric
arguments in Calendar mode even without the Meta modifier.  For example,
`100 C-f' moves point 100 days forward from its present location.


File: emacs,  Node: Move to Beginning or End,  Next: Specified Dates,  Prev: Calendar Unit Motion,  Up: Calendar Motion

Beginning or End of Week, Month or Year
---------------------------------------

   A week (or month, or year) is not just a quantity of days; we think
of weeks (months, years) as starting on particular dates.  So Calendar
mode provides commands to move to the beginning or end of a week, month
or year:

`C-a'
     Move point to start of week (`calendar-beginning-of-week').

`C-e'
     Move point to end of week (`calendar-end-of-week').

`M-a'
     Move point to start of month (`calendar-beginning-of-month').

`M-e'
     Move point to end of month (`calendar-end-of-month').

`M-<'
     Move point to start of year (`calendar-beginning-of-year').

`M->'
     Move point to end of year (`calendar-end-of-year').

   These commands also take numeric arguments as repeat counts, with the
repeat count indicating how many weeks, months, or years to move
backward or forward.

   By default, weeks begin on Sunday.  To make them begin on Monday
instead, set the variable `calendar-week-start-day' to 1.


File: emacs,  Node: Specified Dates,  Prev: Move to Beginning or End,  Up: Calendar Motion

Specified Dates
---------------

   Calendar mode provides commands for moving to a particular date
specified in various ways.

`g d'
     Move point to specified date (`calendar-goto-date').

`o'
     Center calendar around specified month (`calendar-other-month').

`.'
     Move point to today's date (`calendar-goto-today').

   `g d' (`calendar-goto-date') prompts for a year, a month, and a day
of the month, and then moves to that date.  Because the calendar
includes all dates from the beginning of the current era, you must type
the year in its entirety; that is, type `1990', not `90'.

   `o' (`calendar-other-month') prompts for a month and year, then
centers the three-month calendar around that month.

   You can return to today's date with `.' (`calendar-goto-today').


File: emacs,  Node: Scroll Calendar,  Next: Counting Days,  Prev: Calendar Motion,  Up: Calendar/Diary

Scrolling in the Calendar
=========================

   The calendar display scrolls automatically through time when you
move out of the visible portion.  You can also scroll it manually.
Imagine that the calendar window contains a long strip of paper with
the months on it.  Scrolling it means moving the strip so that new
months become visible in the window.

`C-x <'
     Scroll calendar one month forward (`scroll-calendar-left').

`C-x >'
     Scroll calendar one month backward (`scroll-calendar-right').

`C-v'
`<NEXT>'
     Scroll calendar three months forward
     (`scroll-calendar-left-three-months').

`M-v'
`<PRIOR>'
     Scroll calendar three months backward
     (`scroll-calendar-right-three-months').

   The most basic calendar scroll commands scroll by one month at a
time.  This means that there are two months of overlap between the
display before the command and the display after.  `C-x <' scrolls the
calendar contents one month to the left; that is, it moves the display
forward in time.  `C-x >' scrolls the contents to the right, which
moves backwards in time.

   The commands `C-v' and `M-v' scroll the calendar by an entire
"screenful"--three months--in analogy with the usual meaning of these
commands.  `C-v' makes later dates visible and `M-v' makes earlier
dates visible.  These commands take a numeric argument as a repeat
count; in particular, since `C-u' multiplies the next command by four,
typing `C-u C-v' scrolls the calendar forward by a year and typing `C-u
M-v' scrolls the calendar backward by a year.

   The function keys <NEXT> and <PRIOR> are equivalent to `C-v' and
`M-v', just as they are in other modes.


File: emacs,  Node: Counting Days,  Next: General Calendar,  Prev: Scroll Calendar,  Up: Calendar/Diary

Counting Days
=============

`M-='
     Display the number of days in the current region
     (`calendar-count-days-region').

   To determine the number of days in the region, type `M-='
(`calendar-count-days-region').  The numbers of days printed is
_inclusive_; that is, it includes the days specified by mark and point.


File: emacs,  Node: General Calendar,  Next: LaTeX Calendar,  Prev: Counting Days,  Up: Calendar/Diary

Miscellaneous Calendar Commands
===============================

`p d'
     Display day-in-year (`calendar-print-day-of-year').

`C-c C-l'
     Regenerate the calendar window (`redraw-calendar').

`SPC'
     Scroll the next window (`scroll-other-window').

`q'
     Exit from calendar (`exit-calendar').

   To print the number of days elapsed since the start of the year, or
the number of days remaining in the year, type the `p d' command
(`calendar-print-day-of-year').  This displays both of those numbers in
the echo area.  The number of days elapsed includes the selected date.
The number of days remaining does not include that date.

   If the calendar window text gets corrupted, type `C-c C-l'
(`redraw-calendar') to redraw it.  (This can only happen if you use
non-Calendar-mode editing commands.)

   In Calendar mode, you can use `SPC' (`scroll-other-window') to
scroll the other window.  This is handy when you display a list of
holidays or diary entries in another window.

   To exit from the calendar, type `q' (`exit-calendar').  This buries
all buffers related to the calendar, selecting other buffers.  (If a
frame contains a dedicated calendar window, exiting from the calendar
iconifies that frame.)


File: emacs,  Node: LaTeX Calendar,  Next: Holidays,  Prev: General Calendar,  Up: Calendar/Diary

LaTeX Calendar
==============

   The Calendar LaTeX commands produce a buffer of LaTeX code that
prints as a calendar.  Depending on the command you use, the printed
calendar covers the day, week, month or year that point is in.

`t m'
     Generate a one-month calendar (`cal-tex-cursor-month').

`t M'
     Generate a sideways-printing one-month calendar
     (`cal-tex-cursor-month-landscape').

`t d'
     Generate a one-day calendar (`cal-tex-cursor-day').

`t w 1'
     Generate a one-page calendar for one week (`cal-tex-cursor-week').

`t w 2'
     Generate a two-page calendar for one week (`cal-tex-cursor-week2').

`t w 3'
     Generate an ISO-style calendar for one week
     (`cal-tex-cursor-week-iso').

`t w 4'
     Generate a calendar for one Monday-starting week
     (`cal-tex-cursor-week-monday').

`t f w'
     Generate a Filofax-style two-weeks-at-a-glance calendar
     (`cal-tex-cursor-filofax-2week').

`t f W'
     Generate a Filofax-style one-week-at-a-glance calendar
     (`cal-tex-cursor-filofax-week').

`t y'
     Generate a calendar for one year (`cal-tex-cursor-year').

`t Y'
     Generate a sideways-printing calendar for one year
     (`cal-tex-cursor-year-landscape').

`t f y'
     Generate a Filofax-style calendar for one year
     (`cal-tex-cursor-filofax-year').

   Some of these commands print the calendar sideways (in "landscape
mode"), so it can be wider than it is long.  Some of them use Filofax
paper size (3.75in x 6.75in).  All of these commands accept a prefix
argument which specifies how many days, weeks, months or years to print
(starting always with the selected one).

   If the variable `cal-tex-holidays' is non-`nil' (the default), then
the printed calendars show the holidays in `calendar-holidays'.  If the
variable `cal-tex-diary' is non-`nil' (the default is `nil'), diary
entries are included also (in weekly and monthly calendars only).


File: emacs,  Node: Holidays,  Next: Sunrise/Sunset,  Prev: LaTeX Calendar,  Up: Calendar/Diary

Holidays
========

   The Emacs calendar knows about all major and many minor holidays,
and can display them.

`h'
     Display holidays for the selected date
     (`calendar-cursor-holidays').

`Mouse-2 Holidays'
     Display any holidays for the date you click on.

`x'
     Mark holidays in the calendar window (`mark-calendar-holidays').

`u'
     Unmark calendar window (`calendar-unmark').

`a'
     List all holidays for the displayed three months in another window
     (`list-calendar-holidays').

`M-x holidays'
     List all holidays for three months around today's date in another
     window.

`M-x list-holidays'
     List holidays in another window for a specified range of years.

   To see if any holidays fall on a given date, position point on that
date in the calendar window and use the `h' command.  Alternatively,
click on that date with `Mouse-2' and then choose `Holidays' from the
menu that appears.  Either way, this displays the holidays for that
date, in the echo area if they fit there, otherwise in a separate
window.

   To view the distribution of holidays for all the dates shown in the
calendar, use the `x' command.  This displays the dates that are
holidays in a different face (or places a `*' after these dates, if
display with multiple faces is not available).  The command applies both
to the currently visible months and to other months that subsequently
become visible by scrolling.  To turn marking off and erase the current
marks, type `u', which also erases any diary marks (*note Diary::).

   To get even more detailed information, use the `a' command, which
displays a separate buffer containing a list of all holidays in the
current three-month range.  You can use <SPC> in the calendar window to
scroll that list.

   The command `M-x holidays' displays the list of holidays for the
current month and the preceding and succeeding months; this works even
if you don't have a calendar window.  If you want the list of holidays
centered around a different month, use `C-u M-x holidays', which
prompts for the month and year.

   The holidays known to Emacs include United States holidays and the
major Christian, Jewish, and Islamic holidays; also the solstices and
equinoxes.

   The command `M-x list-holidays' displays the list of holidays for a
range of years.  This function asks you for the starting and stopping
years, and allows you to choose all the holidays or one of several
categories of holidays.  You can use this command even if you don't have
a calendar window.

   The dates used by Emacs for holidays are based on _current
practice_, not historical fact.  Historically, for instance, the start
of daylight savings time and even its existence have varied from year to
year, but present United States law mandates that daylight savings time
begins on the first Sunday in April.  When the daylight savings rules
are set up for the United States, Emacs always uses the present
definition, even though it is wrong for some prior years.


File: emacs,  Node: Sunrise/Sunset,  Next: Lunar Phases,  Prev: Holidays,  Up: Calendar/Diary

Times of Sunrise and Sunset
===========================

   Special calendar commands can tell you, to within a minute or two,
the times of sunrise and sunset for any date.

`S'
     Display times of sunrise and sunset for the selected date
     (`calendar-sunrise-sunset').

`Mouse-2 Sunrise/Sunset'
     Display times of sunrise and sunset for the date you click on.

`M-x sunrise-sunset'
     Display times of sunrise and sunset for today's date.

`C-u M-x sunrise-sunset'
     Display times of sunrise and sunset for a specified date.

   Within the calendar, to display the _local times_ of sunrise and
sunset in the echo area, move point to the date you want, and type `S'.
Alternatively, click `Mouse-2' on the date, then choose
`Sunrise/Sunset' from the menu that appears.  The command `M-x
sunrise-sunset' is available outside the calendar to display this
information for today's date or a specified date.  To specify a date
other than today, use `C-u M-x sunrise-sunset', which prompts for the
year, month, and day.

   You can display the times of sunrise and sunset for any location and
any date with `C-u C-u M-x sunrise-sunset'.  This asks you for a
longitude, latitude, number of minutes difference from Coordinated
Universal Time, and date, and then tells you the times of sunrise and
sunset for that location on that date.

   Because the times of sunrise and sunset depend on the location on
earth, you need to tell Emacs your latitude, longitude, and location
name before using these commands.  Here is an example of what to set:

     (setq calendar-latitude 40.1)
     (setq calendar-longitude -88.2)
     (setq calendar-location-name "Urbana, IL")

Use one decimal place in the values of `calendar-latitude' and
`calendar-longitude'.

   Your time zone also affects the local time of sunrise and sunset.
Emacs usually gets time zone information from the operating system, but
if these values are not what you want (or if the operating system does
not supply them), you must set them yourself.  Here is an example:

     (setq calendar-time-zone -360)
     (setq calendar-standard-time-zone-name "CST")
     (setq calendar-daylight-time-zone-name "CDT")

The value of `calendar-time-zone' is the number of minutes difference
between your local standard time and Coordinated Universal Time
(Greenwich time).  The values of `calendar-standard-time-zone-name' and
`calendar-daylight-time-zone-name' are the abbreviations used in your
time zone.  Emacs displays the times of sunrise and sunset _corrected
for daylight savings time_.  *Note Daylight Savings::, for how daylight
savings time is determined.

   As a user, you might find it convenient to set the calendar location
variables for your usual physical location in your `.emacs' file.  And
when you install Emacs on a machine, you can create a `default.el' file
which sets them properly for the typical location of most users of that
machine.  *Note Init File::.


File: emacs,  Node: Lunar Phases,  Next: Other Calendars,  Prev: Sunrise/Sunset,  Up: Calendar/Diary

Phases of the Moon
==================

   These calendar commands display the dates and times of the phases of
the moon (new moon, first quarter, full moon, last quarter).  This
feature is useful for debugging problems that "depend on the phase of
the moon."

`M'
     Display the dates and times for all the quarters of the moon for
     the three-month period shown (`calendar-phases-of-moon').

`M-x phases-of-moon'
     Display dates and times of the quarters of the moon for three
     months around today's date.

   Within the calendar, use the `M' command to display a separate
buffer of the phases of the moon for the current three-month range.  The
dates and times listed are accurate to within a few minutes.

   Outside the calendar, use the command `M-x phases-of-moon' to
display the list of the phases of the moon for the current month and the
preceding and succeeding months.  For information about a different
month, use `C-u M-x phases-of-moon', which prompts for the month and
year.

   The dates and times given for the phases of the moon are given in
local time (corrected for daylight savings, when appropriate); but if
the variable `calendar-time-zone' is void, Coordinated Universal Time
(the Greenwich time zone) is used.  *Note Daylight Savings::.


File: emacs,  Node: Other Calendars,  Next: Diary,  Prev: Lunar Phases,  Up: Calendar/Diary

Conversion To and From Other Calendars
======================================

   The Emacs calendar displayed is _always_ the Gregorian calendar,
sometimes called the "new style" calendar, which is used in most of the
world today.  However, this calendar did not exist before the sixteenth
century and was not widely used before the eighteenth century; it did
not fully displace the Julian calendar and gain universal acceptance
until the early twentieth century.  The Emacs calendar can display any
month since January, year 1 of the current era, but the calendar
displayed is the Gregorian, even for a date at which the Gregorian
calendar did not exist.

   While Emacs cannot display other calendars, it can convert dates to
and from several other calendars.

* Menu:

* Calendar Systems::	   The calendars Emacs understands
			     (aside from Gregorian).
* To Other Calendar::	   Converting the selected date to various calendars.
* From Other Calendar::	   Moving to a date specified in another calendar.
* Mayan Calendar::	   Moving to a date specified in a Mayan calendar.


File: emacs,  Node: Calendar Systems,  Next: To Other Calendar,  Up: Other Calendars

Supported Calendar Systems
--------------------------

   The ISO commercial calendar is used largely in Europe.

   The Julian calendar, named after Julius Caesar, was the one used in
Europe throughout medieval times, and in many countries up until the
nineteenth century.

   Astronomers use a simple counting of days elapsed since noon, Monday,
January 1, 4713 B.C. on the Julian calendar.  The number of days elapsed
is called the _Julian day number_ or the _Astronomical day number_.

   The Hebrew calendar is used by tradition in the Jewish religion.  The
Emacs calendar program uses the Hebrew calendar to determine the dates
of Jewish holidays.  Hebrew calendar dates begin and end at sunset.

   The Islamic calendar is used in many predominantly Islamic countries.
Emacs uses it to determine the dates of Islamic holidays.  There is no
universal agreement in the Islamic world about the calendar; Emacs uses
a widely accepted version, but the precise dates of Islamic holidays
often depend on proclamation by religious authorities, not on
calculations.  As a consequence, the actual dates of observance can vary
slightly from the dates computed by Emacs.  Islamic calendar dates begin
and end at sunset.

   The French Revolutionary calendar was created by the Jacobins after
the 1789 revolution, to represent a more secular and nature-based view
of the annual cycle, and to install a 10-day week in a rationalization
measure similar to the metric system.  The French government officially
abandoned this calendar at the end of 1805.

   The Maya of Central America used three separate, overlapping calendar
systems, the _long count_, the _tzolkin_, and the _haab_.  Emacs knows
about all three of these calendars.  Experts dispute the exact
correlation between the Mayan calendar and our calendar; Emacs uses the
Goodman-Martinez-Thompson correlation in its calculations.

   The Copts use a calendar based on the ancient Egyptian solar
calendar.  Their calendar consists of twelve 30-day months followed by
an extra five-day period.  Once every fourth year they add a leap day
to this extra period to make it six days.  The Ethiopic calendar is
identical in structure, but has different year numbers and month names.

   The Persians use a solar calendar based on a design of Omar Khayyam.
Their calendar consists of twelve months of which the first six have 31
days, the next five have 30 days, and the last has 29 in ordinary years
and 30 in leap years.  Leap years occur in a complicated pattern every
four or five years.

   The Chinese calendar is a complicated system of lunar months arranged
into solar years.  The years go in cycles of sixty, each year containing
either twelve months in an ordinary year or thirteen months in a leap
year; each month has either 29 or 30 days.  Years, ordinary months, and
days are named by combining one of ten "celestial stems" with one of
twelve "terrestrial branches" for a total of sixty names that are
repeated in a cycle of sixty.


File: emacs,  Node: To Other Calendar,  Next: From Other Calendar,  Prev: Calendar Systems,  Up: Other Calendars

Converting To Other Calendars
-----------------------------

   The following commands describe the selected date (the date at point)
in various other calendar systems:

`Mouse-2  Other Calendars'
     Display the date that you click on, expressed in various other
     calendars.

`p c'
     Display ISO commercial calendar equivalent for selected day
     (`calendar-print-iso-date').

`p j'
     Display Julian date for selected day
     (`calendar-print-julian-date').

`p a'
     Display astronomical (Julian) day number for selected day
     (`calendar-print-astro-day-number').

`p h'
     Display Hebrew date for selected day
     (`calendar-print-hebrew-date').

`p i'
     Display Islamic date for selected day
     (`calendar-print-islamic-date').

`p f'
     Display French Revolutionary date for selected day
     (`calendar-print-french-date').

`p C'
     Display Chinese date for selected day
     (`calendar-print-chinese-date').

`p k'
     Display Coptic date for selected day
     (`calendar-print-coptic-date').

`p e'
     Display Ethiopic date for selected day
     (`calendar-print-ethiopic-date').

`p p'
     Display Persian date for selected day
     (`calendar-print-persian-date').

`p m'
     Display Mayan date for selected day (`calendar-print-mayan-date').

   If you are using X, the easiest way to translate a date into other
calendars is to click on it with `Mouse-2', then choose `Other
Calendars' from the menu that appears.  This displays the equivalent
forms of the date in all the calendars Emacs understands, in the form of
a menu.  (Choosing an alternative from this menu doesn't actually do
anything--the menu is used only for display.)

   Put point on the desired date of the Gregorian calendar, then type
the appropriate keys.  The `p' is a mnemonic for "print" since Emacs
"prints" the equivalent date in the echo area.


File: emacs,  Node: From Other Calendar,  Next: Mayan Calendar,  Prev: To Other Calendar,  Up: Other Calendars

Converting From Other Calendars
-------------------------------

   You can use the other supported calendars to specify a date to move
to.  This section describes the commands for doing this using calendars
other than Mayan; for the Mayan calendar, see the following section.

`g c'
     Move to a date specified in the ISO commercial calendar
     (`calendar-goto-iso-date').

`g j'
     Move to a date specified in the Julian calendar
     (`calendar-goto-julian-date').

`g a'
     Move to a date specified in astronomical (Julian) day number
     (`calendar-goto-astro-day-number').

`g h'
     Move to a date specified in the Hebrew calendar
     (`calendar-goto-hebrew-date').

`g i'
     Move to a date specified in the Islamic calendar
     (`calendar-goto-islamic-date').

`g f'
     Move to a date specified in the French Revolutionary calendar
     (`calendar-goto-french-date').

`g C'
     Move to a date specified in the Chinese calendar
     (`calendar-goto-chinese-date').

`g p'
     Move to a date specified in the Persian calendar
     (`calendar-goto-persian-date').

`g k'
     Move to a date specified in the Coptic calendar
     (`calendar-goto-coptic-date').

`g e'
     Move to a date specified in the Ethiopic calendar
     (`calendar-goto-ethiopic-date').

   These commands ask you for a date on the other calendar, move point
to the Gregorian calendar date equivalent to that date, and display the
other calendar's date in the echo area.  Emacs uses strict completion
(*note Completion::) whenever it asks you to type a month name, so you
don't have to worry about the spelling of Hebrew, Islamic, or French
names.

   One common question concerning the Hebrew calendar is the computation
of the anniversary of a date of death, called a "yahrzeit."  The Emacs
calendar includes a facility for such calculations.  If you are in the
calendar, the command `M-x list-yahrzeit-dates' asks you for a range of
years and then displays a list of the yahrzeit dates for those years
for the date given by point.  If you are not in the calendar, this
command first asks you for the date of death and the range of years,
and then displays the list of yahrzeit dates.


File: emacs,  Node: Mayan Calendar,  Prev: From Other Calendar,  Up: Other Calendars

Converting from the Mayan Calendar
----------------------------------

   Here are the commands to select dates based on the Mayan calendar:

`g m l'
     Move to a date specified by the long count calendar
     (`calendar-goto-mayan-long-count-date').

`g m n t'
     Move to the next occurrence of a place in the tzolkin calendar
     (`calendar-next-tzolkin-date').

`g m p t'
     Move to the previous occurrence of a place in the tzolkin calendar
     (`calendar-previous-tzolkin-date').

`g m n h'
     Move to the next occurrence of a place in the haab calendar
     (`calendar-next-haab-date').

`g m p h'
     Move to the previous occurrence of a place in the haab calendar
     (`calendar-previous-haab-date').

`g m n c'
     Move to the next occurrence of a place in the calendar round
     (`calendar-next-calendar-round-date').

`g m p c'
     Move to the previous occurrence of a place in the calendar round
     (`calendar-previous-calendar-round-date').

   To understand these commands, you need to understand the Mayan
calendars.  The "long count" is a counting of days with these units:

     1 kin = 1 day   1 uinal = 20 kin   1 tun = 18 uinal
     1 katun = 20 tun   1 baktun = 20 katun

Thus, the long count date 12.16.11.16.6 means 12 baktun, 16 katun, 11
tun, 16 uinal, and 6 kin.  The Emacs calendar can handle Mayan long
count dates as early as 7.17.18.13.1, but no earlier.  When you use the
`g m l' command, type the Mayan long count date with the baktun, katun,
tun, uinal, and kin separated by periods.

   The Mayan tzolkin calendar is a cycle of 260 days formed by a pair of
independent cycles of 13 and 20 days.  Since this cycle repeats
endlessly, Emacs provides commands to move backward and forward to the
previous or next point in the cycle.  Type `g m p t' to go to the
previous tzolkin date; Emacs asks you for a tzolkin date and moves point
to the previous occurrence of that date.  Similarly, type `g m n t' to
go to the next occurrence of a tzolkin date.

   The Mayan haab calendar is a cycle of 365 days arranged as 18 months
of 20 days each, followed a 5-day monthless period.  Like the tzolkin
cycle, this cycle repeats endlessly, and there are commands to move
backward and forward to the previous or next point in the cycle.  Type
`g m p h' to go to the previous haab date; Emacs asks you for a haab
date and moves point to the previous occurrence of that date.
Similarly, type `g m n h' to go to the next occurrence of a haab date.

   The Maya also used the combination of the tzolkin date and the haab
date.  This combination is a cycle of about 52 years called a _calendar
round_.  If you type `g m p c', Emacs asks you for both a haab and a
tzolkin date and then moves point to the previous occurrence of that
combination.  Use `g m n c' to move point to the next occurrence of a
combination.  These commands signal an error if the haab/tzolkin date
combination you have typed is impossible.

   Emacs uses strict completion (*note Strict Completion::) whenever it
asks you to type a Mayan name, so you don't have to worry about
spelling.


File: emacs,  Node: Diary,  Next: Appointments,  Prev: Other Calendars,  Up: Calendar/Diary

The Diary
=========

   The Emacs diary keeps track of appointments or other events on a
daily basis, in conjunction with the calendar.  To use the diary
feature, you must first create a "diary file" containing a list of
events and their dates.  Then Emacs can automatically pick out and
display the events for today, for the immediate future, or for any
specified date.

   By default, Emacs uses `~/diary' as the diary file.  This is the
same file that the `calendar' utility uses.  A sample `~/diary' file is:

     12/22/1988  Twentieth wedding anniversary!!
     &1/1.       Happy New Year!
     10/22       Ruth's birthday.
     * 21, *:    Payday
     Tuesday--weekly meeting with grad students at 10am
              Supowit, Shen, Bitner, and Kapoor to attend.
     1/13/89     Friday the thirteenth!!
     &thu 4pm    squash game with Lloyd.
     mar 16      Dad's birthday
     April 15, 1989 Income tax due.
     &* 15       time cards due.

This example uses extra spaces to align the event descriptions of most
of the entries.  Such formatting is purely a matter of taste.

   Although you probably will start by creating a diary manually, Emacs
provides a number of commands to let you view, add, and change diary
entries.

* Menu:

* Diary Commands::         Viewing diary entries and associated calendar dates.
* Format of Diary File::   Entering events in your diary.
* Date Formats::	   Various ways you can specify dates.
* Adding to Diary::	   Commands to create diary entries.
* Special Diary Entries::  Anniversaries, blocks of dates, cyclic entries, etc.


File: emacs,  Node: Diary Commands,  Next: Format of Diary File,  Up: Diary

Commands Displaying Diary Entries
---------------------------------

   Once you have created a `~/diary' file, you can use the calendar to
view it.  You can also view today's events outside of Calendar mode.

`d'
     Display all diary entries for the selected date
     (`view-diary-entries').

`Mouse-2 Diary'
     Display all diary entries for the date you click on.

`s'
     Display the entire diary file (`show-all-diary-entries').

`m'
     Mark all visible dates that have diary entries
     (`mark-diary-entries').

`u'
     Unmark the calendar window (`calendar-unmark').

`M-x print-diary-entries'
     Print hard copy of the diary display as it appears.

`M-x diary'
     Display all diary entries for today's date.

`M-x diary-mail-entries'
     Mail yourself email reminders about upcoming diary entries.

   Displaying the diary entries with `d' shows in a separate window the
diary entries for the selected date in the calendar.  The mode line of
the new window shows the date of the diary entries and any holidays
that fall on that date.  If you specify a numeric argument with `d', it
shows all the diary entries for that many successive days.  Thus, `2 d'
displays all the entries for the selected date and for the following
day.

   Another way to display the diary entries for a date is to click
`Mouse-2' on the date, and then choose `Diary' from the menu that
appears.

   To get a broader view of which days are mentioned in the diary, use
the `m' command.  This displays the dates that have diary entries in a
different face (or places a `+' after these dates, if display with
multiple faces is not available).  The command applies both to the
currently visible months and to other months that subsequently become
visible by scrolling.  To turn marking off and erase the current marks,
type `u', which also turns off holiday marks (*note Holidays::).

   To see the full diary file, rather than just some of the entries, use
the `s' command.

   Display of selected diary entries uses the selective display feature
to hide entries that don't apply.

   The diary buffer as you see it is an illusion, so simply printing the
buffer does not print what you see on your screen.  There is a special
command to print hard copy of the diary buffer _as it appears_; this
command is `M-x print-diary-entries'.  It sends the data directly to
the printer.  You can customize it like `lpr-region' (*note Hardcopy::).

   The command `M-x diary' displays the diary entries for the current
date, independently of the calendar display, and optionally for the next
few days as well; the variable `number-of-diary-entries' specifies how
many days to include.  *Note Customizing the Calendar and Diary:
(elisp)Calendar.

   If you put `(diary)' in your `.emacs' file, this automatically
displays a window with the day's diary entries, when you enter Emacs.
The mode line of the displayed window shows the date and any holidays
that fall on that date.

   Many users like to receive notice of events in their diary as email.
To send such mail to yourself, use the command `M-x
diary-mail-entries'.  A prefix argument specifies how many days
(starting with today) to check; otherwise, the variable
`diary-mail-days' says how many days.


File: emacs,  Node: Format of Diary File,  Next: Date Formats,  Prev: Diary Commands,  Up: Diary

The Diary File
--------------

   Your "diary file" is a file that records events associated with
particular dates.  The name of the diary file is specified by the
variable `diary-file'; `~/diary' is the default.  The `calendar'
utility program supports a subset of the format allowed by the Emacs
diary facilities, so you can use that utility to view the diary file,
with reasonable results aside from the entries it cannot understand.

   Each entry in the diary file describes one event and consists of one
or more lines.  An entry always begins with a date specification at the
left margin.  The rest of the entry is simply text to describe the
event.  If the entry has more than one line, then the lines after the
first must begin with whitespace to indicate they continue a previous
entry.  Lines that do not begin with valid dates and do not continue a
preceding entry are ignored.

   You can inhibit the marking of certain diary entries in the calendar
window; to do this, insert an ampersand (`&') at the beginning of the
entry, before the date.  This has no effect on display of the entry in
the diary window; it affects only marks on dates in the calendar
window.  Nonmarking entries are especially useful for generic entries
that would otherwise mark many different dates.

   If the first line of a diary entry consists only of the date or day
name with no following blanks or punctuation, then the diary window
display doesn't include that line; only the continuation lines appear.
For example, this entry:

     02/11/1989
           Bill B. visits Princeton today
           2pm Cognitive Studies Committee meeting
           2:30-5:30 Liz at Lawrenceville
           4:00pm Dentist appt
           7:30pm Dinner at George's
           8:00-10:00pm concert

appears in the diary window without the date line at the beginning.
This style of entry looks neater when you display just a single day's
entries, but can cause confusion if you ask for more than one day's
entries.

   You can edit the diary entries as they appear in the window, but it
is important to remember that the buffer displayed contains the _entire_
diary file, with portions of it concealed from view.  This means, for
instance, that the `C-f' (`forward-char') command can put point at what
appears to be the end of the line, but what is in reality the middle of
some concealed line.

   _Be careful when editing the diary entries!_  Inserting additional
lines or adding/deleting characters in the middle of a visible line
cannot cause problems, but editing at the end of a line may not do what
you expect.  Deleting a line may delete other invisible entries that
follow it.  Before editing the diary, it is best to display the entire
file with `s' (`show-all-diary-entries').


File: emacs,  Node: Date Formats,  Next: Adding to Diary,  Prev: Format of Diary File,  Up: Diary

Date Formats
------------

   Here are some sample diary entries, illustrating different ways of
formatting a date.  The examples all show dates in American order
(month, day, year), but Calendar mode supports European order (day,
month, year) as an option.

     4/20/93  Switch-over to new tabulation system
     apr. 25  Start tabulating annual results
     4/30  Results for April are due
     */25  Monthly cycle finishes
     Friday  Don't leave without backing up files

   The first entry appears only once, on April 20, 1993.  The second and
third appear every year on the specified dates, and the fourth uses a
wildcard (asterisk) for the month, so it appears on the 25th of every
month.  The final entry appears every week on Friday.

   You can use just numbers to express a date, as in `MONTH/DAY' or
`MONTH/DAY/YEAR'.  This must be followed by a nondigit.  In the date
itself, MONTH and DAY are numbers of one or two digits.  The optional
YEAR is also a number, and may be abbreviated to the last two digits;
that is, you can use `11/12/1989' or `11/12/89'.

   Dates can also have the form `MONTHNAME DAY' or `MONTHNAME DAY,
YEAR', where the month's name can be spelled in full or abbreviated to
three characters (with or without a period).  Case is not significant.

   A date may be "generic"; that is, partially unspecified.  Then the
entry applies to all dates that match the specification.  If the date
does not contain a year, it is generic and applies to any year.
Alternatively, MONTH, DAY, or YEAR can be a `*'; this matches any
month, day, or year, respectively.  Thus, a diary entry `3/*/*' matches
any day in March of any year; so does `march *'.

   If you prefer the European style of writing dates--in which the day
comes before the month--type `M-x european-calendar' while in the
calendar, or set the variable `european-calendar-style' to `t' _before_
using any calendar or diary command.  This mode interprets all dates in
the diary in the European manner, and also uses European style for
displaying diary dates.  (Note that there is no comma after the
MONTHNAME in the European style.)  To go back to the (default) American
style of writing dates, type `M-x american-calendar'.

   You can use the name of a day of the week as a generic date which
applies to any date falling on that day of the week.  You can abbreviate
the day of the week to three letters (with or without a period) or spell
it in full; case is not significant.


File: emacs,  Node: Adding to Diary,  Next: Special Diary Entries,  Prev: Date Formats,  Up: Diary

Commands to Add to the Diary
----------------------------

   While in the calendar, there are several commands to create diary
entries:

`i d'
     Add a diary entry for the selected date (`insert-diary-entry').

`i w'
     Add a diary entry for the selected day of the week
     (`insert-weekly-diary-entry').

`i m'
     Add a diary entry for the selected day of the month
     (`insert-monthly-diary-entry').

`i y'
     Add a diary entry for the selected day of the year
     (`insert-yearly-diary-entry').

   You can make a diary entry for a specific date by selecting that date
in the calendar window and typing the `i d' command.  This command
displays the end of your diary file in another window and inserts the
date; you can then type the rest of the diary entry.

   If you want to make a diary entry that applies to a specific day of
the week, select that day of the week (any occurrence will do) and type
`i w'.  This inserts the day-of-week as a generic date; you can then
type the rest of the diary entry.  You can make a monthly diary entry in
the same fashion.  Select the day of the month, use the `i m' command,
and type rest of the entry.  Similarly, you can insert a yearly diary
entry with the `i y' command.

   All of the above commands make marking diary entries by default.  To
make a nonmarking diary entry, give a numeric argument to the command.
For example, `C-u i w' makes a nonmarking weekly diary entry.

   When you modify the diary file, be sure to save the file before
exiting Emacs.

