Mercurial > hg > xemacs-beta
diff man/xemacs/calendar.texi @ 428:3ecd8885ac67 r21-2-22
Import from CVS: tag r21-2-22
author | cvs |
---|---|
date | Mon, 13 Aug 2007 11:28:15 +0200 |
parents | |
children | abe6d1db359e |
line wrap: on
line diff
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/man/xemacs/calendar.texi Mon Aug 13 11:28:15 2007 +0200 @@ -0,0 +1,2304 @@ +@node Calendar/Diary, Sorting, Reading Mail, Top +@section Calendar Mode and the Diary +@cindex calendar +@findex calendar + + Emacs provides the functions of a desk calendar, with a diary of +planned or past events. To enter the calendar, type @kbd{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 @kbd{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. + + @kbd{Button2} in the calendar brings up a menu of operations on a +particular date; @kbd{Buttons3} brings up a menu of commonly used +calendar features that are independent of any particular date. To exit +the calendar, type @kbd{q}. @xref{Calendar, Customizing the Calendar +and Diary,, elisp, The Emacs Lisp Reference Manual}, 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. +* Mark and Region:: Remembering dates, the mark ring. +* 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. +* Calendar Customization:: Altering the behavior of the features above. +@end menu + +@node Calendar Motion, Scroll Calendar, Calendar/Diary, Calendar/Diary +@subsection Movement in the Calendar + +@cindex moving inside 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. +@end menu + +@node Calendar Unit Motion, Move to Beginning or End, Calendar Motion, Calendar Motion +@subsubsection Motion by Integral Days, Weeks, Months, Years + + 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. + +@table @kbd +@item C-f +Move point one day forward (@code{calendar-forward-day}). +@item C-b +Move point one day backward (@code{calendar-backward-day}). +@item C-n +Move point one week forward (@code{calendar-forward-week}). +@item C-p +Move point one week backward (@code{calendar-backward-week}). +@item M-@} +Move point one month forward (@code{calendar-forward-month}). +@item M-@{ +Move point one month backward (@code{calendar-backward-month}). +@item C-x ] +Move point one year forward (@code{calendar-forward-year}). +@item C-x [ +Move point one year backward (@code{calendar-backward-year}). +@end table + +@kindex C-f @r{(Calendar mode)} +@findex calendar-forward-day +@kindex C-b @r{(Calendar mode)} +@findex calendar-backward-day +@kindex C-n @r{(Calendar mode)} +@findex calendar-forward-week +@kindex C-p @r{(Calendar mode)} +@findex calendar-backward-week + The day and week commands are natural analogues of the usual Emacs +commands for moving by characters and by lines. Just as @kbd{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 @kbd{C-p} +moves to the same day in the previous week. + + The arrow keys are equivalent to @kbd{C-f}, @kbd{C-b}, @kbd{C-n} and +@kbd{C-p}, just as they normally are in other modes. + +@kindex M-@} @r{(Calendar mode)} +@findex calendar-forward-month +@kindex M-@{ @r{(Calendar mode)} +@findex calendar-backward-month +@kindex C-x ] @r{(Calendar mode)} +@findex calendar-forward-year +@kindex C-x [ @r{(Calendar mode)} +@findex calendar-forward-year + The commands for motion by months and years work like those for +weeks, but move a larger distance. The month commands @kbd{M-@}} and +@kbd{M-@{} move forward or backward by an entire month's time. The +year commands @kbd{C-x ]} and @w{@kbd{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, +@kbd{100 C-f} moves point 100 days forward from its present location. + +@node Move to Beginning or End, Specified Dates, Calendar Unit Motion, Calendar Motion +@subsubsection 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: + +@table @kbd +@kindex C-a @r{(Calendar mode)} +@findex calendar-beginning-of-week +@item C-a +Move point to start of week (@code{calendar-beginning-of-week}). +@kindex C-e @r{(Calendar mode)} +@findex calendar-end-of-week +@item C-e +Move point to end of week (@code{calendar-end-of-week}). +@kindex M-a @r{(Calendar mode)} +@findex calendar-beginning-of-month +@item M-a +Move point to start of month (@code{calendar-beginning-of-month}). +@kindex M-e @r{(Calendar mode)} +@findex calendar-end-of-month +@item M-e +Move point to end of month (@code{calendar-end-of-month}). +@kindex M-< @r{(Calendar mode)} +@findex calendar-beginning-of-year +@item M-< +Move point to start of year (@code{calendar-beginning-of-year}). +@kindex M-> @r{(Calendar mode)} +@findex calendar-end-of-year +@item M-> +Move point to end of year (@code{calendar-end-of-year}). +@end table + + 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. + +@vindex calendar-week-start-day +@cindex weeks, which day they start on +@cindex calendar, first day of week + By default, weeks begin on Sunday. To make them begin on Monday +instead, set the variable @code{calendar-week-start-day} to 1. + +@node Specified Dates,,Move to Beginning or End, Calendar Motion +@subsubsection Particular Dates + + Calendar mode provides commands for moving to a particular date +specified in various ways. + +@table @kbd +@item g d +Move point to specified date (@code{calendar-goto-date}). +@item o +Center calendar around specified month (@code{calendar-other-month}). +@item . +Move point to today's date (@code{calendar-goto-today}). +@end table + +@kindex g d @r{(Calendar mode)} +@findex calendar-goto-date + @kbd{g d} (@code{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 @samp{1990}, not @samp{90}. + +@kindex o @r{(Calendar mode)} +@findex calendar-other-month + @kbd{o} (@code{calendar-other-month}) prompts for a month and year, +then centers the three-month calendar around that month. + +@kindex . @r{(Calendar mode)} +@findex calendar-goto-today + You can return to today's date with @kbd{.}@: +(@code{calendar-goto-today}). + +@node Scroll Calendar, Mark and Region, Calendar Motion, Calendar/Diary +@subsection Scrolling the Calendar through Time + +@cindex 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. + +@table @kbd +@item C-x < +Scroll calendar one month forward (@code{scroll-calendar-left}). +@item C-x > +Scroll calendar one month backward (@code{scroll-calendar-right}). +@item C-v +@itemx @key{NEXT} +Scroll calendar three months forward +(@code{scroll-calendar-left-three-months}). +@item M-v +@itemx @key{PRIOR} +Scroll calendar three months backward +(@code{scroll-calendar-right-three-months}). +@end table + +@kindex C-x < @r{(Calendar mode)} +@findex scroll-calendar-left +@kindex C-x > @r{(Calendar mode)} +@findex scroll-calendar-right + 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. @kbd{C-x <} scrolls +the calendar contents one month to the left; that is, it moves the +display forward in time. @kbd{C-x >} scrolls the contents to the +right, which moves backwards in time. + +@kindex C-v @r{(Calendar mode)} +@findex scroll-calendar-left-three-months +@kindex M-v @r{(Calendar mode)} +@findex scroll-calendar-right-three-months + The commands @kbd{C-v} and @kbd{M-v} scroll the calendar by an entire +``screenful''---three months---in analogy with the usual meaning of +these commands. @kbd{C-v} makes later dates visible and @kbd{M-v} makes +earlier dates visible. These commands take a numeric argument as a +repeat count; in particular, since @kbd{C-u} multiplies the next command +by four, typing @kbd{C-u C-v} scrolls the calendar forward by a year and +typing @kbd{C-u M-v} scrolls the calendar backward by a year. + + The function keys @key{NEXT} and @key{PRIOR} are equivalent to +@kbd{C-v} and @kbd{M-v}, just as they are in other modes. + + +@node Mark and Region, General Calendar, Scroll Calendar, Calendar/Diary +@subsection The Mark and the Region + + The concept of the mark applies to the calendar just as to any other +buffer, but it marks a @emph{date}, not a @emph{position} in the buffer. +The region consists of the days between the mark and point (including +the starting and stopping dates). + +@table @kbd +@item C-SPC +Set the mark to today's date (@code{calendar-set-mark}). +@item C-@@ +The same. +@item C-x C-x +Interchange mark and point (@code{calendar-exchange-point-and-mark}). +@item M-= +Display the number of days in the current region +(@code{calendar-count-days-region}). +@end table + +@kindex C-@@ @r{(Calendar mode)} +@kindex C-SPC @r{(Calendar mode)} +@findex calendar-set-mark +@kindex C-x C-x @r{(Calendar mode)} +@findex calendar-exchange-point-and-mark + You set the mark in the calendar, as in any other buffer, by using @kbd{C-@@} +or @kbd{C-SPC} (@code{calendar-set-mark}). You return to the marked date +with the command @kbd{C-x C-x} (@code{calendar-exchange-point-and-mark}) +which puts the mark where point was and point where mark was. The calendar +is scrolled as necessary, if the marked date was not visible on the +screen. This does not change the extent of the region. + +@kindex M-= @r{(Calendar mode)} +@findex calendar-count-days-region + To determine the number of days in the region, type @kbd{M-=} +(@code{calendar-count-days-region}). The numbers of days printed is +@emph{inclusive}; that is, it includes the days specified by mark and +point. + +@cindex mark ring + The main use of the mark in the calendar is to remember dates that you may +want to go back to. To make this feature more useful, the mark ring +(@pxref{Mark Ring}) operates exactly as in other buffers: Emacs remembers +16 previous locations of the mark. To return to a marked date, type @kbd{C-u +C-SPC} (or @kbd{C-u C-@@}); this is the command @code{calendar-set-mark} given +a numeric argument. It moves point to where the mark was, restores the mark +from the ring of former marks, and stores the previous point at the end of +the mark ring. So, repeated use of this command moves point through all +the old marks on the ring, one by one. + +@node General Calendar, LaTeX Calendar, Mark and Region, Calendar/Diary +@subsection Miscellaneous Calendar Commands + +@table @kbd +@item p d +Display day-in-year (@code{calendar-print-day-of-year}). +@item ? +Briefly describe calendar commands (@code{describe-calendar-mode}). +@item C-c C-l +Regenerate the calendar window (@code{redraw-calendar}). +@item SPC +Scroll the next window (@code{scroll-other-window}). +@item q +Exit from calendar (@code{exit-calendar}). +@end table + +@kindex p d @r{(Calendar mode)} +@cindex day of year +@findex calendar-print-day-of-year + If you want to know how many days have elapsed since the start of +the year, or the number of days remaining in the year, type the @kbd{p d} +command (@code{calendar-print-day-of-year}). This displays both +of those numbers in the echo area. + +@kindex ? @r{(Calendar mode)} +@findex describe-calendar-mode + To display a brief description of the calendar commands, type @kbd{?} +(@code{describe-calendar-mode}). For a fuller description, type @kbd{C-h m}. + +@kindex SPC @r{(Calendar mode)} +@findex scroll-other-window + You can use @kbd{SPC} (@code{scroll-other-window}) to scroll the other +window. This is handy when you display a list of holidays or diary entries +in another window. + +@kindex C-c C-l @r{(Calendar mode)} +@findex redraw-calendar + If the calendar window text gets corrupted, type @kbd{C-c C-l} +(@code{redraw-calendar}) to redraw it. (This can only happen if you use +non-Calendar-mode editing commands.) + +@kindex SPC @r{(Calendar mode)} + In Calendar mode, you can use @kbd{SPC} (@code{scroll-other-window}) +to scroll the other window. This is handy when you display a list of +holidays or diary entries in another window. + +@kindex q @r{(Calendar mode)} +@findex exit-calendar + To exit from the calendar, type @kbd{q} (@code{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.) + +@node LaTeX Calendar, Holidays, General Calendar, Calendar/Diary +@section LaTeX Calendar +@cindex calendar and La@TeX{} + + The Calendar La@TeX{} commands produce a buffer of La@TeX{} 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. + +@kindex t @r{(Calendar mode)} +@table @kbd +@item t m +Generate a one-month calendar (@code{cal-tex-cursor-month}). +@item t M +Generate a sideways-printing one-month calendar +(@code{cal-tex-cursor-month-landscape}). +@item t d +Generate a one-day calendar +(@code{cal-tex-cursor-day}). +@item t w 1 +Generate a one-page calendar for one week +(@code{cal-tex-cursor-week}). +@item t w 2 +Generate a two-page calendar for one week +(@code{cal-tex-cursor-week2}). +@item t w 3 +Generate an ISO-style calendar for one week +(@code{cal-tex-cursor-week-iso}). +@item t w 4 +Generate a calendar for one Monday-starting week +(@code{cal-tex-cursor-week-monday}). +@item t f w +Generate a Filofax-style two-weeks-at-a-glance calendar +(@code{cal-tex-cursor-filofax-2week}). +@item t f W +Generate a Filofax-style one-week-at-a-glance calendar +(@code{cal-tex-cursor-filofax-week}). +@item t y +Generate a calendar for one year +(@code{cal-tex-cursor-year}). +@item t Y +Generate a sideways-printing calendar for one year +(@code{cal-tex-cursor-year-landscape}). +@item t f y +Generate a Filofax-style calendar for one year +(@code{cal-tex-cursor-filofax-year}). +@end table + + 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 @code{cal-tex-holidays} is non-@code{nil} (the +default), then the printed calendars show the holidays in +@code{calendar-holidays}. If the variable @code{cal-tex-diary} is +non-@code{nil} (the default is @code{nil}), diary entries are included +also (in weekly and monthly calendars only). + +@node Holidays, Sunrise/Sunset, LaTeX Calendar, Calendar/Diary +@subsection Holidays +@cindex holidays + + The Emacs calendar knows about all major and many minor holidays, +and can display them. + +@table @kbd +@item h +Display holidays for the selected date +(@code{calendar-cursor-holidays}). +@item Button2 Holidays +Display any holidays for the date you click on. +@item x +Mark holidays in the calendar window (@code{mark-calendar-holidays}). +@item u +Unmark calendar window (@code{calendar-unmark}). +@item a +List all holidays for the displayed three months in another window +(@code{list-calendar-holidays}). +@item M-x holidays +List all holidays for three months around today's date in another +window. +@item M-x list-holidays +List holidays in another window for a specified range of years. +@end table + +@kindex h @r{(Calendar mode)} +@findex calendar-cursor-holidays + To see if any holidays fall on a given date, position point on that +date in the calendar window and use the @kbd{h} command. Alternatively, +click on that date with @kbd{Button2} and then choose @kbd{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. + +@kindex x @r{(Calendar mode)} +@findex mark-calendar-holidays +@kindex u @r{(Calendar mode)} +@findex calendar-unmark + To view the distribution of holidays for all the dates shown in the +calendar, use the @kbd{x} command. This displays the dates that are +holidays in a different face (or places a @samp{*} 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 @kbd{u}, which also erases any diary marks (@pxref{Diary}). + +@kindex a @r{(Calendar mode)} +@findex list-calendar-holidays + To get even more detailed information, use the @kbd{a} command, which +displays a separate buffer containing a list of all holidays in the +current three-month range. You can use @key{SPC} in the calendar window +to scroll that list. + +@findex holidays + The command @kbd{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 @kbd{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. + +@findex list-holidays + The command @kbd{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 @emph{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. + +@node Sunrise/Sunset, Lunar Phases, Holidays, Calendar/Diary +@subsection Times of Sunrise and Sunset +@cindex sunrise and sunset + + Special calendar commands can tell you, to within a minute or two, the +times of sunrise and sunset for any date. + +@table @kbd +@item S +Display times of sunrise and sunset for the selected date +(@code{calendar-sunrise-sunset}). +@item Button2 Sunrise/Sunset +Display times of sunrise and sunset for the date you click on. +@item M-x sunrise-sunset +Display times of sunrise and sunset for today's date. +@item C-u M-x sunrise-sunset +Display times of sunrise and sunset for a specified date. +@end table + +@kindex S @r{(Calendar mode)} +@findex calendar-sunrise-sunset +@findex sunrise-sunset + Within the calendar, to display the @emph{local times} of sunrise and +sunset in the echo area, move point to the date you want, and type +@kbd{S}. Alternatively, click @kbd{Button2} on the date, then choose +@kbd{Sunrise/Sunset} from the menu that appears. The command @kbd{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 @kbd{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 @kbd{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: + +@vindex calendar-location-name +@vindex calendar-longitude +@vindex calendar-latitude +@example +(setq calendar-latitude 40.1) +(setq calendar-longitude -88.2) +(setq calendar-location-name "Urbana, IL") +@end example + +@noindent +Use one decimal place in the values of @code{calendar-latitude} and +@code{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: + +@vindex calendar-time-zone +@vindex calendar-standard-time-zone-name +@vindex calendar-daylight-time-zone-name +@example +(setq calendar-time-zone -360) +(setq calendar-standard-time-zone-name "CST") +(setq calendar-daylight-time-zone-name "CDT") +@end example + +@noindent +The value of @code{calendar-time-zone} is the number of minutes +difference between your local standard time and Coordinated Universal +Time (Greenwich time). The values of +@code{calendar-standard-time-zone-name} and +@code{calendar-daylight-time-zone-name} are the abbreviations used in +your time zone. Emacs displays the times of sunrise and sunset +@emph{corrected for daylight savings time}. @xref{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 @file{.emacs} file. +And when you install Emacs on a machine, you can create a +@file{default.el} file which sets them properly for the typical location +of most users of that machine. @xref{Init File}. + +@node Lunar Phases, Other Calendars, Sunrise/Sunset, Calendar/Diary +@subsection Phases of the Moon +@cindex phases of the moon +@cindex moon, phases of + + 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.'' + +@table @kbd +@item M +Display the dates and times for all the quarters of the moon for the +three-month period shown (@code{calendar-phases-of-moon}). +@item M-x phases-of-moon +Display dates and times of the quarters of the moon for three months around +today's date. +@end table + +@kindex M @r{(Calendar mode)} +@findex calendar-phases-of-moon + Within the calendar, use the @kbd{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. + +@findex phases-of-moon + Outside the calendar, use the command @kbd{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 @kbd{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 @code{calendar-time-zone} is void, Coordinated Universal +Time (the Greenwich time zone) is used. @xref{Daylight Savings}. + +@node Other Calendars, Calendar Systems, Lunar Phases, Calendar/Diary +@subsection Conversion To and From Other Calendars + +@cindex Gregorian calendar + The Emacs calendar displayed is @emph{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. +@end menu + + If you are interested in these calendars, you can convert dates one at a +time. Put point on the desired date of the Gregorian calendar and press the +appropriate keys. The @kbd{p} is a mnemonic for ``print'' since Emacs +``prints' the equivalent date in the echo area. +@node Calendar Systems, To Other Calendar, Other Calendars, Other Calendars +@section Supported Calendar Systems + +@cindex ISO commercial calendar + The ISO commercial calendar is used largely in Europe. + +@cindex Julian calendar + 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. + +@cindex Julian day numbers +@cindex astronomical day numbers + 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 @emph{Julian day number} or the @emph{Astronomical day number}. + +@cindex Hebrew calendar + 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. + +@cindex Islamic calendar + 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. + +@cindex French Revolutionary calendar + 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. + +@cindex Mayan calendar + The Maya of Central America used three separate, overlapping calendar +systems, the @emph{long count}, the @emph{tzolkin}, and the @emph{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. + +@cindex Coptic calendar +@cindex Ethiopic calendar + 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. + +@cindex Persian calendar + 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. + +@cindex Chinese calendar + 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. + +@node To Other Calendar, From Other Calendar, Calendar Systems, Other Calendars +@section Converting To Other Calendars + + The following commands describe the selected date (the date at point) +in various other calendar systems: + +@table @kbd +@item Button2 Other Calendars +Display the date that you click on, expressed in various other calendars. +@kindex p @r{(Calendar mode)} +@findex calendar-print-iso-date +@item p c +Display ISO commercial calendar equivalent for selected day +(@code{calendar-print-iso-date}). +@findex calendar-print-julian-date +@item p j +Display Julian date for selected day (@code{calendar-print-julian-date}). +@findex calendar-print-astro-day-number +@item p a +Display astronomical (Julian) day number for selected day +(@code{calendar-print-astro-day-number}). +@findex calendar-print-hebrew-date +@item p h +Display Hebrew date for selected day (@code{calendar-print-hebrew-date}). +@findex calendar-print-islamic-date +@item p i +Display Islamic date for selected day (@code{calendar-print-islamic-date}). +@findex calendar-print-french-date +@item p f +Display French Revolutionary date for selected day +(@code{calendar-print-french-date}). +@findex calendar-print-chinese-date +@item p C +Display Chinese date for selected day +(@code{calendar-print-chinese-date}). +@findex calendar-print-coptic-date +@item p k +Display Coptic date for selected day +(@code{calendar-print-coptic-date}). +@findex calendar-print-ethiopic-date +@item p e +Display Ethiopic date for selected day +(@code{calendar-print-ethiopic-date}). +@findex calendar-print-persian-date +@item p p +Display Persian date for selected day +(@code{calendar-print-persian-date}). +@findex calendar-print-mayan-date +@item p m +Display Mayan date for selected day (@code{calendar-print-mayan-date}). +@end table + + If you are using X, the easiest way to translate a date into other +calendars is to click on it with @kbd{Button2}, then choose @kbd{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 @kbd{p} is a mnemonic for ``print'' since Emacs +``prints'' the equivalent date in the echo area. + +@node From Other Calendar, Mayan Calendar, To Other Calendar, Other Calendars +@section 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. + +@kindex g @var{char} @r{(Calendar mode)} +@findex calendar-goto-iso-date +@findex calendar-goto-julian-date +@findex calendar-goto-astro-day-number +@findex calendar-goto-hebrew-date +@findex calendar-goto-islamic-date +@findex calendar-goto-french-date +@findex calendar-goto-chinese-date +@findex calendar-goto-persian-date +@findex calendar-goto-coptic-date +@findex calendar-goto-ethiopic-date +@table @kbd +@item g c +Move to a date specified in the ISO commercial calendar +(@code{calendar-goto-iso-date}). +@item g j +Move to a date specified in the Julian calendar +(@code{calendar-goto-julian-date}). +@item g a +Move to a date specified in astronomical (Julian) day number +(@code{calendar-goto-astro-day-number}). +@item g h +Move to a date specified in the Hebrew calendar +(@code{calendar-goto-hebrew-date}). +@item g i +Move to a date specified in the Islamic calendar +(@code{calendar-goto-islamic-date}). +@item g f +Move to a date specified in the French Revolutionary calendar +(@code{calendar-goto-french-date}). +@item g C +Move to a date specified in the Chinese calendar +(@code{calendar-goto-chinese-date}). +@item g p +Move to a date specified in the Persian calendar +(@code{calendar-goto-persian-date}). +@item g k +Move to a date specified in the Coptic calendar +(@code{calendar-goto-coptic-date}). +@item g e +Move to a date specified in the Ethiopic calendar +(@code{calendar-goto-ethiopic-date}). +@end table + + 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 +(@pxref{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. + +@findex list-yahrzeit-dates +@cindex yahrzeits + 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 @kbd{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. + +@node Mayan Calendar, Diary ,From Other Calendar ,Other Calendars +@subsection Converting from the Mayan Calendar + + Here are the commands to select dates based on the Mayan calendar: + +@table @kbd +@item g m l +Move to a date specified by the long count calendar +(@code{calendar-goto-mayan-long-count-date}). +@item g m n t +Move to the next occurrence of a place in the +tzolkin calendar (@code{calendar-next-tzolkin-date}). +@item g m p t +Move to the previous occurrence of a place in the +tzolkin calendar (@code{calendar-previous-tzolkin-date}). +@item g m n h +Move to the next occurrence of a place in the +haab calendar (@code{calendar-next-haab-date}). +@item g m p h +Move to the previous occurrence of a place in the +haab calendar (@code{calendar-previous-haab-date}). +@item g m n c +Move to the next occurrence of a place in the +calendar round (@code{calendar-next-calendar-round-date}). +@item g m p c +Move to the previous occurrence of a place in the +calendar round (@code{calendar-previous-calendar-round-date}). +@end table + +@cindex Mayan long count + To understand these commands, you need to understand the Mayan calendars. +The @dfn{long count} is a counting of days with these units: + +@display +1 kin = 1 day@ @ @ 1 uinal = 20 kin@ @ @ 1 tun = 18 uinal +1 katun = 20 tun@ @ @ 1 baktun = 20 katun +@end display + +@kindex g m l @r{(Calendar mode)} +@findex calendar-goto-mayan-long-count-date +@noindent +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 +@kbd{g m l} command, type the Mayan long count date with the baktun, +katun, tun, uinal, and kin separated by periods. + +@findex calendar-previous-tzolkin-date +@findex calendar-next-tzolkin-date +@cindex Mayan tzolkin calendar + 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 @kbd{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 @kbd{g m n t} +to go to the next occurrence of a tzolkin date. + +@findex calendar-previous-haab-date +@findex calendar-next-haab-date +@cindex Mayan haab calendar + 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 +@kbd{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 @kbd{g m n h} to go to the next occurrence of a haab +date. + +@c This is omitted because it is too long for smallbook format. +@c @findex calendar-previous-calendar-round-date +@findex calendar-next-calendar-round-date +@cindex Mayan calendar round + 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 +@emph{calendar round}. If you type @kbd{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 @kbd{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 (@pxref{Completion}) whenever it +asks you to type a Mayan name, so you don't have to worry about +spelling. + +@node Diary, Calendar Customization, Mayan Calendar, Calendar/Diary +@subsection The Diary +@cindex 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 @dfn{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 @file{~/diary} as the diary file. This is the +same file that the @code{calendar} utility uses. A sample +@file{~/diary} file is: + +@example +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. +@end example + +@noindent +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. You can also share diary entries with other users +(@pxref{Included Diary Files}). + +@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. +@end menu + +@node Diary Commands, Format of Diary File, Diary, Diary +@subsection Commands Displaying Diary Entries + + Once you have created a @file{~/diary} file, you can use the calendar +to view it. You can also view today's events outside of Calendar mode. + +@table @kbd +@item d +Display all diary entries for the selected date +(@code{view-diary-entries}). +@item Button2 Diary +Display all diary entries for the date you click on. +@item s +Display the entire diary file (@code{show-all-diary-entries}). +@item m +Mark all visible dates that have diary entries +(@code{mark-diary-entries}). +@item u +Unmark the calendar window (@code{calendar-unmark}). +@item M-x print-diary-entries +Print hard copy of the diary display as it appears. +@item M-x diary +Display all diary entries for today's date. +@item M-x diary-mail-entries +Mail yourself email reminders about upcoming diary entries. +@end table + +@kindex d @r{(Calendar mode)} +@findex view-diary-entries + Displaying the diary entries with @kbd{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 @kbd{d}, +it shows all the diary entries for that many successive days. Thus, +@kbd{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 +@kbd{Button2} on the date, and then choose @kbd{Diary} from the menu +that appears. + +@kindex m @r{(Calendar mode)} +@findex mark-diary-entries +@kindex u @r{(Calendar mode)} +@findex calendar-unmark + To get a broader view of which days are mentioned in the diary, use +the @kbd{m} command. This displays the dates that have diary entries +in a different face (or places a @samp{+} 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 @kbd{u}, which also turns off holiday marks +(@pxref{Holidays}). + +@kindex s @r{(Calendar mode)} +@findex show-all-diary-entries + To see the full diary file, rather than just some of the entries, use +the @kbd{s} command. + + Display of selected diary entries uses the selective display feature +to hide entries that don't apply. + +@findex print-diary-entries + 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 @emph{as it appears}; +this command is @kbd{M-x print-diary-entries}. It sends the data +directly to the printer. You can customize it like @code{lpr-region} +(@pxref{Hardcopy}). + +@findex diary + The command @kbd{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 @code{number-of-diary-entries} specifies +how many days to include (@pxref{Customization}). + + If you put @code{(diary)} in your @file{.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. + +@findex diary-mail-entries +@vindex diary-mail-days + Many users like to receive notice of events in their diary as email. +To send such mail to yourself, use the command @kbd{M-x +diary-mail-entries}. A prefix argument specifies how many days +(starting with today) to check; otherwise, the variable +@code{diary-mail-days} says how many days. + +@node Format of Diary File, Date Formats, Diary Commands, Diary +@subsection The Diary File +@cindex diary file + +@vindex diary-file + Your @dfn{diary file} is a file that records events associated with +particular dates. The name of the diary file is specified by the +variable @code{diary-file}; @file{~/diary} is the default. The +@code{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 (@samp{&}) 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: + +@example +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 +@end example + +@noindent +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 @emph{entire} +diary file, with portions of it concealed from view. This means, for +instance, that the @kbd{C-f} (@code{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. + + @emph{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 @kbd{s} (@code{show-all-diary-entries}). + +@node Date Formats,Adding to Diary ,Format of Diary File, Diary +@subsection 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. + +@example +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 +@end example + + 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 +@samp{@var{month}/@var{day}} or @samp{@var{month}/@var{day}/@var{year}}. +This must be followed by a nondigit. In the date itself, @var{month} +and @var{day} are numbers of one or two digits. The optional @var{year} +is also a number, and may be abbreviated to the last two digits; that +is, you can use @samp{11/12/1989} or @samp{11/12/89}. + + Dates can also have the form @samp{@var{monthname} @var{day}} or +@samp{@var{monthname} @var{day}, @var{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 @dfn{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, @var{month}, @var{day}, or @var{year} can be a @samp{*}; +this matches any month, day, or year, respectively. Thus, a diary entry +@samp{3/*/*} matches any day in March of any year; so does @samp{march +*}. + +@vindex european-calendar-style +@findex european-calendar +@findex american-calendar + If you prefer the European style of writing dates---in which the day +comes before the month---type @kbd{M-x european-calendar} while in the +calendar, or set the variable @code{european-calendar-style} to @code{t} +@emph{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 @var{monthname} in the European style.) To go back to the (default) +American style of writing dates, type @kbd{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. + +@node Adding to Diary, Special Diary Entries, Date Formats, Diary +@subsection Commands to Add to the Diary + + While in the calendar, there are several commands to create diary +entries: + +@table @kbd +@item i d +Add a diary entry for the selected date (@code{insert-diary-entry}). +@item i w +Add a diary entry for the selected day of the week (@code{insert-weekly-diary-entry}). +@item i m +Add a diary entry for the selected day of the month (@code{insert-monthly-diary-entry}). +@item i y +Add a diary entry for the selected day of the year (@code{insert-yearly-diary-entry}). +@end table + +@kindex i d @r{(Calendar mode)} +@findex insert-diary-entry + You can make a diary entry for a specific date by selecting that date +in the calendar window and typing the @kbd{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. + +@kindex i w @r{(Calendar mode)} +@findex insert-weekly-diary-entry +@kindex i m @r{(Calendar mode)} +@findex insert-monthly-diary-entry +@kindex i y @r{(Calendar mode)} +@findex insert-yearly-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 +@kbd{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 @kbd{i m} +command, and type rest of the entry. Similarly, you can insert a yearly +diary entry with the @kbd{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, @kbd{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. + +@node Special Diary Entries,, Adding to Diary, Diary +@subsection Special Diary Entries + + In addition to entries based on calendar dates, the diary file can +contain @dfn{sexp entries} for regular events such as anniversaries. +These entries are based on Lisp expressions (sexps) that Emacs evaluates +as it scans the diary file. Instead of a date, a sexp entry contains +@samp{%%} followed by a Lisp expression which must begin and end with +parentheses. The Lisp expression determines which dates the entry +applies to. + + Calendar mode provides commands to insert certain commonly used +sexp entries: + +@table @kbd +@item i a +Add an anniversary diary entry for the selected date +(@code{insert-anniversary-diary-entry}). +@item i b +Add a block diary entry for the current region +(@code{insert-block-diary-entry}). +@item i c +Add a cyclic diary entry starting at the date +(@code{insert-cyclic-diary-entry}). +@end table + +@kindex i a @r{(Calendar mode)} +@findex insert-anniversary-diary-entry + If you want to make a diary entry that applies to the anniversary of a +specific date, move point to that date and use the @kbd{i a} command. +This displays the end of your diary file in another window and inserts +the anniversary description; you can then type the rest of the diary +entry. The entry looks like this: + +@findex diary-anniversary + The effect of @kbd{i a} is to add a @code{diary-anniversary} sexp to your +diary file. You can also add one manually, for instance: + +@example +%%(diary-anniversary 10 31 1948) Arthur's birthday +@end example + +@noindent +This entry applies to October 31 in any year after 1948; @samp{10 31 +1948} specifies the date. (If you are using the European calendar +style, the month and day are interchanged.) The reason this expression +requires a beginning year is that advanced diary functions can use it to +calculate the number of elapsed years. + + A @dfn{block} diary entry applies to a specified range of consecutive +dates. Here is a block diary entry that applies to all dates from June +24, 1990 through July 10, 1990: + +@findex diary-block +@example +%%(diary-block 6 24 1990 7 10 1990) Vacation +@end example + +@noindent +The @samp{6 24 1990} indicates the starting date and the @samp{7 10 1990} +indicates the stopping date. (Again, if you are using the European calendar +style, the month and day are interchanged.) + +@kindex i b @r{(Calendar mode)} +@findex insert-block-diary-entry + To insert a block entry, place point and the mark on the two +dates that begin and end the range, and type @kbd{i b}. This command +displays the end of your diary file in another window and inserts the +block description; you can then type the diary entry. + +@kindex i c @r{(Calendar mode)} +@findex insert-cyclic-diary-entry + @dfn{Cyclic} diary entries repeat after a fixed interval of days. To +create one, select the starting date and use the @kbd{i c} command. The +command prompts for the length of interval, then inserts the entry, +which looks like this: + +@findex diary-cyclic +@example +%%(diary-cyclic 50 3 1 1990) Renew medication +@end example + +@noindent +This entry applies to March 1, 1990 and every 50th day following; +@samp{3 1 1990} specifies the starting date. (If you are using the +European calendar style, the month and day are interchanged.) + + All three of these commands make marking diary entries. To insert a +nonmarking entry, give a numeric argument to the command. For example, +@kbd{C-u i a} makes a nonmarking anniversary diary entry. + + Marking sexp diary entries in the calendar is @emph{extremely} +time-consuming, since every date visible in the calendar window must be +individually checked. So it's a good idea to make sexp diary entries +nonmarking (with @samp{&}) when possible. + + Another sophisticated kind of sexp entry, a @dfn{floating} diary entry, +specifies a regularly occurring event by offsets specified in days, +weeks, and months. It is comparable to a crontab entry interpreted by +the @code{cron} utility. Here is a nonmarking, floating diary entry +that applies to the last Thursday in November: + +@findex diary-float +@example +&%%(diary-float 11 4 -1) American Thanksgiving +@end example + +@noindent +The 11 specifies November (the eleventh month), the 4 specifies Thursday +(the fourth day of the week, where Sunday is numbered zero), and the +@minus{}1 specifies ``last'' (1 would mean ``first'', 2 would mean +``second'', @minus{}2 would mean ``second-to-last'', and so on). The +month can be a single month or a list of months. Thus you could change +the 11 above to @samp{'(1 2 3)} and have the entry apply to the last +Thursday of January, February, and March. If the month is @code{t}, the +entry applies to all months of the year.@refill + + The sexp feature of the diary allows you to specify diary entries +based on any Emacs Lisp expression. You can use the library of built-in +functions or you can write your own functions. The built-in functions +include the ones shown in this section, plus a few others (@pxref{Sexp +Diary Entries}). + + The generality of sexps lets you specify any diary entry that you can +describe algorithmically. Suppose you get paid on the 21st of the month +if it is a weekday, and to the Friday before if the 21st is on a +weekend. The diary entry + +@example +&%%(let ((dayname (calendar-day-of-week date)) + (day (car (cdr date)))) + (or (and (= day 21) (memq dayname '(1 2 3 4 5))) + (and (memq day '(19 20)) (= dayname 5))) + ) Pay check deposited +@end example + +@noindent +to just those dates. This example illustrates how the sexp can depend +on the variable @code{date}; this variable is a list (@var{month} +@var{day} @var{year}) that gives the Gregorian date for which the diary +entries are being found. If the value of the sexp is @code{t}, the +entry applies to that date. If the sexp evaluates to @code{nil}, the +entry does @emph{not} apply to that date. + + +@node Calendar Customization,,Diary, Calendar/Diary +@subsection Customizing the Calendar and Diary + + There are many customizations that you can use to make the calendar and +diary suit your personal tastes. + +@menu +* Calendar Customizing:: Defaults you can set. +* Holiday Customizing:: Defining your own holidays. +* Date Display Format:: Changing the format. +* Time Display Format:: Changing the format. +* Daylight Savings:: Changing the default. +* Diary Customizing:: Defaults you can set. +* Hebrew/Islamic Entries:: How to obtain them. +* Fancy Diary Display:: Enhancing the diary display, sorting entries. +* Included Diary Files:: Sharing a common diary file. +* Sexp Diary Entries:: Fancy things you can do. +* Appt Customizing:: Customizing appointment reminders. +@end menu + +@node Calendar Customizing +@subsubsection Customizing the Calendar +@vindex view-diary-entries-initially + + If you set the variable @code{view-diary-entries-initially} to +@code{t}, calling up the calendar automatically displays the diary +entries for the current date as well. The diary dates appear only if +the current date is visible. If you add both of the following lines to +your @file{.emacs} file:@refill + +@example +(setq view-diary-entries-initially t) +(calendar) +@end example + +@noindent +this displays both the calendar and diary windows whenever you start Emacs. + +@vindex view-calendar-holidays-initially + Similarly, if you set the variable +@code{view-calendar-holidays-initially} to @code{t}, entering the +calendar automatically displays a list of holidays for the current +three-month period. The holiday list appears in a separate +window. + +@vindex mark-diary-entries-in-calendar + You can set the variable @code{mark-diary-entries-in-calendar} to +@code{t} in order to mark any dates with diary entries. This takes +effect whenever the calendar window contents are recomputed. There are +two ways of marking these dates: by changing the face (@pxref{Faces}), +if the display supports that, or by placing a plus sign (@samp{+}) +beside the date otherwise. + +@vindex mark-holidays-in-calendar + Similarly, setting the variable @code{mark-holidays-in-calendar} to +@code{t} marks holiday dates, either with a change of face or with an +asterisk (@samp{*}). + +@vindex calendar-holiday-marker +@vindex diary-entry-marker + The variable @code{calendar-holiday-marker} specifies how to mark a +date as being a holiday. Its value may be a character to insert next to +the date, or a face name to use for displaying the date. Likewise, the +variable @code{diary-entry-marker} specifies how to mark a date that has +diary entries. The calendar creates faces named @code{holiday-face} and +@code{diary-face} for these purposes; those symbols are the default +values of these variables, when Emacs supports multiple faces on your +terminal. + +@vindex calendar-load-hook + The variable @code{calendar-load-hook} is a normal hook run when the +calendar package is first loaded (before actually starting to display +the calendar). + +@vindex initial-calendar-window-hook + Starting the calendar runs the normal hook +@code{initial-calendar-window-hook}. Recomputation of the calendar +display does not run this hook. But if you leave the calendar with the +@kbd{q} command and reenter it, the hook runs again.@refill + +@vindex today-visible-calendar-hook + The variable @code{today-visible-calendar-hook} is a normal hook run +after the calendar buffer has been prepared with the calendar when the +current date is visible in the window. One use of this hook is to +replace today's date with asterisks; to do that, use the hook function +@code{calendar-star-date}. + +@findex calendar-star-date +@example +(add-hook 'today-visible-calendar-hook 'calendar-star-date) +@end example + +@noindent +Another standard hook function marks the current date, either by +changing its face or by adding an asterisk. Here's how to use it: + +@findex calendar-mark-today +@example +(add-hook 'today-visible-calendar-hook 'calendar-mark-today) +@end example + +@noindent +@vindex calendar-today-marker +The variable @code{calendar-today-marker} specifies how to mark today's +date. Its value should be a character to insert next to the date or a +face name to use for displaying the date. A face named +@code{calendar-today-face} is provided for this purpose; that symbol is +the default for this variable when Emacs supports multiple faces on your +terminal. + +@vindex today-invisible-calendar-hook +@noindent + A similar normal hook, @code{today-invisible-calendar-hook} is run if +the current date is @emph{not} visible in the window. + +@node Holiday Customizing +@subsubsection Customizing the Holidays + +@vindex calendar-holidays +@vindex christian-holidays +@vindex hebrew-holidays +@vindex islamic-holidays + Emacs knows about holidays defined by entries on one of several lists. +You can customize these lists of holidays to your own needs, adding or +deleting holidays. The lists of holidays that Emacs uses are for +general holidays (@code{general-holidays}), local holidays +(@code{local-holidays}), Christian holidays (@code{christian-holidays}), +Hebrew (Jewish) holidays (@code{hebrew-holidays}), Islamic (Moslem) +holidays (@code{islamic-holidays}), and other holidays +(@code{other-holidays}). + +@vindex general-holidays + The general holidays are, by default, holidays common throughout the +United States. To eliminate these holidays, set @code{general-holidays} +to @code{nil}. + +@vindex local-holidays + There are no default local holidays (but sites may supply some). You +can set the variable @code{local-holidays} to any list of holidays, as +described below. + +@vindex all-christian-calendar-holidays +@vindex all-hebrew-calendar-holidays +@vindex all-islamic-calendar-holidays + By default, Emacs does not include all the holidays of the religions +that it knows, only those commonly found in secular calendars. For a +more extensive collection of religious holidays, you can set any (or +all) of the variables @code{all-christian-calendar-holidays}, +@code{all-hebrew-calendar-holidays}, or +@code{all-islamic-calendar-holidays} to @code{t}. If you want to +eliminate the religious holidays, set any or all of the corresponding +variables @code{christian-holidays}, @code{hebrew-holidays}, and +@code{islamic-holidays} to @code{nil}.@refill + +@vindex other-holidays + You can set the variable @code{other-holidays} to any list of +holidays. This list, normally empty, is intended for individual use. + +@cindex holiday forms + Each of the lists (@code{general-holidays}, @code{local-holidays}, +@code{christian-holidays}, @code{hebrew-holidays}, +@code{islamic-holidays}, and @code{other-holidays}) is a list of +@dfn{holiday forms}, each holiday form describing a holiday (or +sometimes a list of holidays). + + Here is a table of the possible kinds of holiday form. Day numbers +and month numbers count starting from 1, but ``dayname'' numbers +count Sunday as 0. The element @var{string} is always the +name of the holiday, as a string. + +@table @code +@item (holiday-fixed @var{month} @var{day} @var{string}) +A fixed date on the Gregorian calendar. @var{month} and @var{day} are +numbers, @var{string} is the name of the holiday. + +@item (holiday-float @var{month} @var{dayname} @var{k} @var{string}) +The @var{k}th @var{dayname} in @var{month} on the Gregorian calendar +(@var{dayname}=0 for Sunday, and so on); negative @var{k} means count back +from the end of the month. @var{string} is the name of the holiday. + +@item (holiday-hebrew @var{month} @var{day} @var{string}) +A fixed date on the Hebrew calendar. @var{month} and @var{day} are +numbers, @var{string} is the name of the holiday. + +@item (holiday-islamic @var{month} @var{day} @var{string}) +A fixed date on the Islamic calendar. @var{month} and @var{day} are +numbers, @var{string} is the name of the holiday. + +@item (holiday-julian @var{month} @var{day} @var{string}) +A fixed date on the Julian calendar. @var{month} and @var{day} are +numbers, @var{string} is the name of the holiday. + +@item (holiday-sexp @var{sexp} @var{string}) +A date calculated by the Lisp expression @var{sexp}. The expression +should use the variable @code{year} to compute and return the date of a +holiday, or @code{nil} if the holiday doesn't happen this year. The +value of @var{sexp} must represent the date as a list of the form +@code{(@var{month} @var{day} @var{year})}. @var{string} is the name of +the holiday. + +@item (if @var{condition} @var{holiday-form} &optional @var{holiday-form}) +A holiday that happens only if @var{condition} is true. + +@item (@var{function} @r{[}@var{args}@r{]}) +A list of dates calculated by the function @var{function}, called with +arguments @var{args}. +@end table + + For example, suppose you want to add Bastille Day, celebrated in +France on July 14. You can do this by adding the following line +to your @file{.emacs} file: + +@smallexample +(setq other-holidays '((holiday-fixed 7 14 "Bastille Day"))) +@end smallexample + +@noindent +The holiday form @code{(holiday-fixed 7 14 "Bastille Day")} specifies the +fourteenth day of the seventh month (July). + + Many holidays occur on a specific day of the week, at a specific time +of month. Here is a holiday form describing Hurricane Supplication Day, +celebrated in the Virgin Islands on the fourth Monday in August: + +@smallexample +(holiday-float 8 1 4 "Hurricane Supplication Day") +@end smallexample + +@noindent +Here the 8 specifies August, the 1 specifies Monday (Sunday is 0, +Tuesday is 2, and so on), and the 4 specifies the fourth occurrence in +the month (1 specifies the first occurrence, 2 the second occurrence, +@minus{}1 the last occurrence, @minus{}2 the second-to-last occurrence, and +so on). + + You can specify holidays that occur on fixed days of the Hebrew, +Islamic, and Julian calendars too. For example, + +@smallexample +(setq other-holidays + '((holiday-hebrew 10 2 "Last day of Hanukkah") + (holiday-islamic 3 12 "Mohammed's Birthday") + (holiday-julian 4 2 "Jefferson's Birthday"))) +@end smallexample + +@noindent +adds the last day of Hanukkah (since the Hebrew months are numbered with +1 starting from Nisan), the Islamic feast celebrating Mohammed's +birthday (since the Islamic months are numbered from 1 starting with +Muharram), and Thomas Jefferson's birthday, which is 2 April 1743 on the +Julian calendar. + + To include a holiday conditionally, use either Emacs Lisp's @code{if} or the +@code{holiday-sexp} form. For example, American presidential elections +occur on the first Tuesday after the first Monday in November of years +divisible by 4: + +@smallexample +(holiday-sexp (if (= 0 (% year 4)) + (calendar-gregorian-from-absolute + (1+ (calendar-dayname-on-or-before + 1 (+ 6 (calendar-absolute-from-gregorian + (list 11 1 year)))))) + "US Presidential Election")) +@end smallexample + +@noindent +or + +@smallexample +(if (= 0 (% displayed-year 4)) + (fixed 11 + (extract-calendar-day + (calendar-gregorian-from-absolute + (1+ (calendar-dayname-on-or-before + 1 (+ 6 (calendar-absolute-from-gregorian + (list 11 1 displayed-year))))))) + "US Presidential Election")) +@end smallexample + + Some holidays just don't fit into any of these forms because special +calculations are involved in their determination. In such cases you +must write a Lisp function to do the calculation. To include eclipses, +for example, add @code{(eclipses)} to @code{other-holidays} +and write an Emacs Lisp function @code{eclipses} that returns a +(possibly empty) list of the relevant Gregorian dates among the range +visible in the calendar window, with descriptive strings, like this: + +@smallexample +(((6 27 1991) "Lunar Eclipse") ((7 11 1991) "Solar Eclipse") ... ) +@end smallexample + +@node Date Display Format +@subsubsection Date Display Format +@vindex calendar-date-display-form + + You can customize the manner of displaying dates in the diary, in mode +lines, and in messages by setting @code{calendar-date-display-form}. +This variable holds a list of expressions that can involve the variables +@code{month}, @code{day}, and @code{year}, which are all numbers in +string form, and @code{monthname} and @code{dayname}, which are both +alphabetic strings. In the American style, the default value of this +list is as follows: + +@smallexample +((if dayname (concat dayname ", ")) monthname " " day ", " year) +@end smallexample + +@noindent +while in the European style this value is the default: + +@smallexample +((if dayname (concat dayname ", ")) day " " monthname " " year) +@end smallexample + ++@noindent +The ISO standard date representation is this: + +@smallexample +(year "-" month "-" day) +@end smallexample + +@noindent +This specifies a typical American format: + +@smallexample +(month "/" day "/" (substring year -2)) +@end smallexample + +@node Time Display Format +@subsubsection Time Display Format +@vindex calendar-time-display-form + + The calendar and diary by default display times of day in the +conventional American style with the hours from 1 through 12, minutes, +and either @samp{am} or @samp{pm}. If you prefer the European style, +also known in the US as military, in which the hours go from 00 to 23, +you can alter the variable @code{calendar-time-display-form}. This +variable is a list of expressions that can involve the variables +@code{12-hours}, @code{24-hours}, and @code{minutes}, which are all +numbers in string form, and @code{am-pm} and @code{time-zone}, which are +both alphabetic strings. The default value of +@code{calendar-time-display-form} is as follows: + +@smallexample +(12-hours ":" minutes am-pm + (if time-zone " (") time-zone (if time-zone ")")) +@end smallexample + +@noindent +Here is a value that provides European style times: + +@smallexample +(24-hours ":" minutes + (if time-zone " (") time-zone (if time-zone ")")) +@end smallexample + +@noindent +gives military-style times like @samp{21:07 (UT)} if time zone names are +defined, and times like @samp{21:07} if they are not. + +@node Daylight Savings +@subsubsection Daylight Savings Time +@cindex daylight savings time + + Emacs understands the difference between standard time and daylight +savings time---the times given for sunrise, sunset, solstices, +equinoxes, and the phases of the moon take that into account. The rules +for daylight savings time vary from place to place and have also varied +historically from year to year. To do the job properly, Emacs needs to +know which rules to use. + + Some operating systems keep track of the rules that apply to the place +where you are; on these systems, Emacs gets the information it needs +from the system automatically. If some or all of this information is +missing, Emacs fills in the gaps with the rules currently used in +Cambridge, Massachusetts. If the resulting rules are not what you want, +you can tell Emacs the rules to use by setting certain variables. + +@vindex calendar-daylight-savings-starts +@vindex calendar-daylight-savings-ends + If the default choice of rules is not appropriate for your location, +you can tell Emacs the rules to use by setting the variables +@code{calendar-daylight-savings-starts} and +@code{calendar-daylight-savings-ends}. Their values should be Lisp +expressions that refer to the variable @code{year}, and evaluate to the +Gregorian date on which daylight savings time starts or (respectively) +ends, in the form of a list @code{(@var{month} @var{day} @var{year})}. +The values should be @code{nil} if your area does not use daylight +savings time. + + Emacs uses these expressions to determine the starting date of +daylight savings time for the holiday list and for correcting times of +day in the solar and lunar calculations. + + The values for Cambridge, Massachusetts are as follows: + +@example +@group +(calendar-nth-named-day 1 0 4 year) +(calendar-nth-named-day -1 0 10 year) +@end group +@end example + +@noindent +That is, the first 0th day (Sunday) of the fourth month (April) in +the year specified by @code{year}, and the last Sunday of the tenth month +(October) of that year. If daylight savings time were +changed to start on October 1, you would set +@code{calendar-daylight-savings-starts} to this: + +@example +(list 10 1 year) +@end example + + For a more complex example, suppose daylight savings time begins on +the first of Nisan on the Hebrew calendar. You should set +@code{calendar-daylight-savings-starts} to this value: + +@example +(calendar-gregorian-from-absolute + (calendar-absolute-from-hebrew + (list 1 1 (+ year 3760)))) +@end example + +@noindent +because Nisan is the first month in the Hebrew calendar and the Hebrew +year differs from the Gregorian year by 3760 at Nisan. + + If there is no daylight savings time at your location, or if you want +all times in standard time, set @code{calendar-daylight-savings-starts} +and @code{calendar-daylight-savings-ends} to @code{nil}. + +@vindex calendar-daylight-time-offset + The variable @code{calendar-daylight-time-offset} specifies the +difference between daylight savings time and standard time, measured in +minutes. The value for Cambridge, Massachusetts is 60. + +@c @vindex calendar-daylight-savings-starts-time too long! +@vindex calendar-daylight-savings-ends-time + The two variables @code{calendar-daylight-savings-starts-time} and +@code{calendar-daylight-savings-ends-time} specify the number of minutes +after midnight local time when the transition to and from daylight +savings time should occur. For Cambridge, Massachusetts both variables' +values are 120. + +@node Diary Customizing +@subsubsection Customizing the Diary + +@vindex holidays-in-diary-buffer + Ordinarily, the mode line of the diary buffer window indicates any +holidays that fall on the date of the diary entries. The process of +checking for holidays can take several seconds, so including holiday +information delays the display of the diary buffer noticeably. If you'd +prefer to have a faster display of the diary buffer but without the +holiday information, set the variable @code{holidays-in-diary-buffer} to +@code{nil}.@refill + +@vindex number-of-diary-entries + The variable @code{number-of-diary-entries} controls the number of +days of diary entries to be displayed at one time. It affects the +initial display when @code{view-diary-entries-initially} is @code{t}, as +well as the command @kbd{M-x diary}. For example, the default value is +1, which says to display only the current day's diary entries. If the +value is 2, both the current day's and the next day's entries are +displayed. The value can also be a vector of seven elements: for +example, if the value is @code{[0 2 2 2 2 4 1]} then no diary entries +appear on Sunday, the current date's and the next day's diary entries +appear Monday through Thursday, Friday through Monday's entries appear +on Friday, while on Saturday only that day's entries appear. + +@vindex print-diary-entries-hook +@findex print-diary-entries + The variable @code{print-diary-entries-hook} is a normal hook run +after preparation of a temporary buffer containing just the diary +entries currently visible in the diary buffer. (The other, irrelevant +diary entries are really absent from the temporary buffer; in the diary +buffer, they are merely hidden.) The default value of this hook does +the printing with the command @code{lpr-buffer}. If you want to use a +different command to do the printing, just change the value of this +hook. Other uses might include, for example, rearranging the lines into +order by day and time. + +@vindex diary-date-forms + You can customize the form of dates in your diary file, if neither the +standard American nor European styles suits your needs, by setting the +variable @code{diary-date-forms}. This variable is a list of patterns +for recognizing a date. Each date pattern is a list whose elements may +be regular expressions (@pxref{Regexps}) or the symbols +@code{month}, @code{day}, @code{year}, @code{monthname}, and +@code{dayname}. All these elements serve as patterns that match certain +kinds of text in the diary file. In order for the date pattern, as a +whole, to match, all of its elements must match consecutively. + + A regular expression in a date pattern matches in its usual fashion, +using the standard syntax table altered so that @samp{*} is a word +constituent. + + The symbols @code{month}, @code{day}, @code{year}, @code{monthname}, +and @code{dayname} match the month number, day number, year number, +month name, and day name of the date being considered. The symbols that +match numbers allow leading zeros; those that match names allow +three-letter abbreviations and capitalization. All the symbols can +match @samp{*}; since @samp{*} in a diary entry means ``any day'', ``any +month'', and so on, it should match regardless of the date being +considered. + + The default value of @code{diary-date-forms} in the American style is +this: + +@example +((month "/" day "[^/0-9]") + (month "/" day "/" year "[^0-9]") + (monthname " *" day "[^,0-9]") + (monthname " *" day ", *" year "[^0-9]") + (dayname "\\W")) +@end example + +@noindent +Emacs matches of the diary entries with the date forms is done with the +standard syntax table from Fundamental mode +(@pxref{Syntax Tables,,,lispref,XEmacs Lisp Reference Manual}), +but with the @samp{*} changed so that it is a word constituent.@refill + + The date patterns in the list must be @emph{mutually exclusive} and +must not match any portion of the diary entry itself, just the date and +one character of whitespace. If, to be mutually exclusive, the pattern +must match a portion of the diary entry text---beyond the whitespace +that ends the date---then the first element of the date pattern +@emph{must} be @code{backup}. This causes the date recognizer to back +up to the beginning of the current word of the diary entry, after +finishing the match. Even if you use @code{backup}, the date pattern +must absolutely not match more than a portion of the first word of the +diary entry. The default value of @code{diary-date-forms} in the +European style is this list: + +@example +((day "/" month "[^/0-9]") + (day "/" month "/" year "[^0-9]") + (backup day " *" monthname "\\W+\\<[^*0-9]") + (day " *" monthname " *" year "[^0-9]") + (dayname "\\W")) +@end example + +@noindent +Notice the use of @code{backup} in the third pattern, because it needs +to match part of a word beyond the date itself to distinguish it from +the fourth pattern. + +@node Hebrew/Islamic Entries +@subsubsection Hebrew- and Islamic-Date Diary Entries + + Your diary file can have entries based on Hebrew or Islamic dates, as +well as entries based on the world-standard Gregorian calendar. +However, because recognition of such entries is time-consuming and most +people don't use them, you must explicitly enable their use. If you +want the diary to recognize Hebrew-date diary entries, for example, +you must do this: + +@vindex nongregorian-diary-listing-hook +@vindex nongregorian-diary-marking-hook +@findex list-hebrew-diary-entries +@findex mark-hebrew-diary-entries +@smallexample +(add-hook 'nongregorian-diary-listing-hook 'list-hebrew-diary-entries) +(add-hook 'nongregorian-diary-marking-hook 'mark-hebrew-diary-entries) +@end smallexample + +@noindent +If you want Islamic-date entries, do this: + +@findex list-islamic-diary-entries +@findex mark-islamic-diary-entries +@smallexample +(add-hook 'nongregorian-diary-listing-hook 'list-islamic-diary-entries) +(add-hook 'nongregorian-diary-marking-hook 'mark-islamic-diary-entries) +@end smallexample + + Hebrew- and Islamic-date diary entries have the same formats as +Gregorian-date diary entries, except that @samp{H} precedes a Hebrew +date and @samp{I} precedes an Islamic date. Moreover, because the +Hebrew and Islamic month names are not uniquely specified by the first +three letters, you may not abbreviate them. For example, a diary entry +for the Hebrew date Heshvan 25 could look like this: + +@smallexample +HHeshvan 25 Happy Hebrew birthday! +@end smallexample + +@noindent +and would appear in the diary for any date that corresponds to Heshvan 25 +on the Hebrew calendar. And here is Islamic-date diary entry that matches +Dhu al-Qada 25: + +@smallexample +IDhu al-Qada 25 Happy Islamic birthday! +@end smallexample + +@noindent +and would appear in the diary for any date that corresponds to Dhu al-Qada 25 +on the Islamic calendar. + + As with Gregorian-date diary entries, Hebrew- and Islamic-date entries +are nonmarking if they are preceded with an ampersand (@samp{&}). + + Here is a table of commands used in the calendar to create diary entries +that match the selected date and other dates that are similar in the Hebrew +or Islamic calendar: + +@table @kbd +@item i h d +Add a diary entry for the Hebrew date corresponding to the selected date +(@code{insert-hebrew-diary-entry}). +@item i h m +Add a diary entry for the day of the Hebrew month corresponding to the +selected date (@code{insert-monthly-hebrew-diary-entry}). This diary +entry matches any date that has the same Hebrew day-within-month as the +selected date. +@item i h y +Add a diary entry for the day of the Hebrew year corresponding to the +selected date (@code{insert-yearly-hebrew-diary-entry}). This diary +entry matches any date which has the same Hebrew month and day-within-month +as the selected date. +@item i i d +Add a diary entry for the Islamic date corresponding to the selected date +(@code{insert-islamic-diary-entry}). +@item i i m +Add a diary entry for the day of the Islamic month corresponding to the +selected date (@code{insert-monthly-islamic-diary-entry}). +@item i i y +Add a diary entry for the day of the Islamic year corresponding to the +selected date (@code{insert-yearly-islamic-diary-entry}). +@end table + +@findex insert-hebrew-diary-entry +@findex insert-monthly-hebrew-diary-entry +@findex insert-yearly-hebrew-diary-entry +@findex insert-islamic-diary-entry +@findex insert-monthly-islamic-diary-entry +@findex insert-yearly-islamic-diary-entry + These commands work much like the corresponding commands for ordinary +diary entries: they apply to the date that point is on in the calendar +window, and what they do is insert just the date portion of a diary entry +at the end of your diary file. You must then insert the rest of the +diary entry. + +@node Fancy Diary Display +@subsubsection Fancy Diary Display +@vindex diary-display-hook +@findex simple-diary-display + + Diary display works by preparing the diary buffer and then running the +hook @code{diary-display-hook}. The default value of this hook +(@code{simple-diary-display}) hides the irrelevant diary entries and +then displays the buffer. However, if you specify the hook as follows, + +@cindex diary buffer +@findex fancy-diary-display +@example +(add-hook 'diary-display-hook 'fancy-diary-display) +@end example + +@noindent +this enables fancy diary display. It displays diary entries and +holidays by copying them into a special buffer that exists only for the +sake of display. Copying to a separate buffer provides an opportunity +to change the displayed text to make it prettier---for example, to sort +the entries by the dates they apply to. + + As with simple diary display, you can print a hard copy of the buffer +with @code{print-diary-entries}. To print a hard copy of a day-by-day +diary for a week by positioning point on Sunday of that week, type +@kbd{7 d} and then do @kbd{M-x print-diary-entries}. As usual, the +inclusion of the holidays slows down the display slightly; you can speed +things up by setting the variable @code{holidays-in-diary-buffer} to +@code{nil}. + +@vindex diary-list-include-blanks + Ordinarily, the fancy diary buffer does not show days for which there are +no diary entries, even if that day is a holiday. If you want such days to be +shown in the fancy diary buffer, set the variable +@code{diary-list-include-blanks} to @code{t}.@refill + +@cindex sorting diary entries + If you use the fancy diary display, you can use the normal hook +@code{list-diary-entries-hook} to sort each day's diary entries by their +time of day. Add this line to your @file{.emacs} file: + +@findex sort-diary-entries +@example +(add-hook 'list-diary-entries-hook 'sort-diary-entries t) +@end example + +@noindent +For each day, this sorts diary entries that begin with a recognizable +time of day according to their times. Diary entries without times come +first within each day. + +@node Included Diary Files +@subsubsection Included Diary Files + + Fancy diary display also has the ability to process included diary +files. This permits a group of people to share a diary file for events +that apply to all of them. Lines in the diary file of this form: + +@smallexample +#include "@var{filename}" +@end smallexample + +@noindent +includes the diary entries from the file @var{filename} in the fancy +diary buffer. The include mechanism is recursive, so that included files +can include other files, and so on; you must be careful not to have a +cycle of inclusions, of course. Here is how to enable the include +facility: + +@vindex list-diary-entries-hook +@vindex mark-diary-entries-hook +@findex include-other-diary-files +@findex mark-included-diary-files +@smallexample +(add-hook 'list-diary-entries-hook 'include-other-diary-files) +(add-hook 'mark-diary-entries-hook 'mark-included-diary-files) +@end smallexample + +The include mechanism works only with the fancy diary display, because +ordinary diary display shows the entries directly from your diary file. + +@node Sexp Diary Entries +@subsubsection Sexp Entries and the Fancy Diary Display +@cindex sexp diary entries + + Sexp diary entries allow you to do more than just have complicated +conditions under which a diary entry applies. If you use the fancy +diary display, sexp entries can generate the text of the entry depending +on the date itself. For example, an anniversary diary entry can insert +the number of years since the anniversary date into the text of the +diary entry. Thus the @samp{%d} in this dairy entry: + +@findex diary-anniversary +@smallexample +%%(diary-anniversary 10 31 1948) Arthur's birthday (%d years old) +@end smallexample + +@noindent +gets replaced by the age, so on October 31, 1990 the entry appears in +the fancy diary buffer like this: + +@smallexample +Arthur's birthday (42 years old) +@end smallexample + +@noindent +If the diary file instead contains this entry: + +@smallexample +%%(diary-anniversary 10 31 1948) Arthur's %d%s birthday +@end smallexample + +@noindent +the entry in the fancy diary buffer for October 31, 1990 appears like this: + +@smallexample +Arthur's 42nd birthday +@end smallexample + + Similarly, cyclic diary entries can interpolate the number of repetitions +that have occurred: + +@findex diary-cyclic +@smallexample +%%(diary-cyclic 50 1 1 1990) Renew medication (%d%s time) +@end smallexample + +@noindent +looks like this: + +@smallexample +Renew medication (5th time) +@end smallexample + +@noindent +in the fancy diary display on September 8, 1990. + + The generality of sexp diary entries lets you specify any diary entry +that you can describe algorithmically. A sexp diary entry contains an +expression that computes whether the entry applies to any given date. +If its value is non-@code{nil}, the entry applies to that date; +otherwise, it does not. The expression can use the variable @code{date} +to find the date being considered; its value is a list (@var{month} +@var{day} @var{year}) that refers to the Gregorian calendar. + + Suppose you get paid on the 21st of the month if it is a weekday, and +on the Friday before if the 21st is on a weekend. Here is how to write +a sexp diary entry that matches those dates: + +@smallexample +&%%(let ((dayname (calendar-day-of-week date)) + (day (car (cdr date)))) + (or (and (= day 21) (memq dayname '(1 2 3 4 5))) + (and (memq day '(19 20)) (= dayname 5))) + ) Pay check deposited +@end smallexample + +@noindent +applies to just those dates. This example illustrates how the sexp can +depend on the variable @code{date}; this variable is a list (@var{month} +@var{day} @var{year}) that gives the Gregorian date for which the diary +entries are being found. If the value of the expression is @code{t}, +the entry applies to that date. If the expression evaluates to +@code{nil}, the entry does @emph{not} apply to that date. + + The following sexp diary entries take advantage of the ability (in the fancy +diary display) to concoct diary entries whose text varies based on the date: + +@findex diary-sunrise-sunset +@findex diary-phases-of-moon +@findex diary-day-of-year +@findex diary-iso-date +@findex diary-julian-date +@findex diary-astro-day-number +@findex diary-hebrew-date +@findex diary-islamic-date +@findex diary-french-date +@findex diary-mayan-date +@table @code +@item %%(diary-sunrise-sunset) +Make a diary entry for the local times of today's sunrise and sunset. +@item %%(diary-phases-of-moon) +Make a diary entry for the phases (quarters) of the moon. +@item %%(diary-day-of-year) +Make a diary entry with today's day number in the current year and the number +of days remaining in the current year. +@item %%(diary-iso-date) +Make a diary entry with today's equivalent ISO commercial date. +@item %%(diary-julian-date) +Make a diary entry with today's equivalent date on the Julian calendar. +@item %%(diary-astro-day-number) +Make a diary entry with today's equivalent astronomical (Julian) day number. +@item %%(diary-hebrew-date) +Make a diary entry with today's equivalent date on the Hebrew calendar. +@item %%(diary-islamic-date) +Make a diary entry with today's equivalent date on the Islamic calendar. +@item %%(diary-french-date) +Make a diary entry with today's equivalent date on the French Revolutionary +calendar. +@item %%(diary-mayan-date) +Make a diary entry with today's equivalent date on the Mayan calendar. +@end table + +@noindent +Thus including the diary entry + +@smallexample +&%%(diary-hebrew-date) +@end smallexample + +@noindent +causes every day's diary display to contain the equivalent date on the +Hebrew calendar, if you are using the fancy diary display. (With simple +diary display, the line @samp{&%%(diary-hebrew-date)} appears in the +diary for any date, but does nothing particularly useful.) + + These functions can be used to construct sexp diary entries based on +the Hebrew calendar in certain standard ways: + +@cindex rosh hodesh +@findex diary-rosh-hodesh +@cindex parasha, weekly +@findex diary-parasha +@cindex candle lighting times +@findex diary-sabbath-candles +@cindex omer count +@findex diary-omer +@cindex yahrzeits +@findex diary-yahrzeit +@table @code +@item %%(diary-rosh-hodesh) +Make a diary entry that tells the occurrence and ritual announcement of each +new Hebrew month. +@item %%(diary-parasha) +Make a Saturday diary entry that tells the weekly synagogue scripture reading. +@item %%(diary-sabbath-candles) +Make a Friday diary entry that tells the @emph{local time} of Sabbath +candle lighting. +@item %%(diary-omer) +Make a diary entry that gives the omer count, when appropriate. +@item %%(diary-yahrzeit @var{month} @var{day} @var{year}) @var{name} +Make a diary entry marking the anniversary of a date of death. The date +is the @emph{Gregorian} (civil) date of death. The diary entry appears +on the proper Hebrew calendar anniversary and on the day before. (In +the European style, the order of the parameters is changed to @var{day}, +@var{month}, @var{year}.) +@end table + +@node Appt Customizing +@subsubsection Customizing Appointment Reminders + + You can specify exactly how Emacs reminds you of an appointment, and +how far in advance it begins doing so, by setting these variables: + +@vindex appt-message-warning-time +@vindex appt-audible +@vindex appt-visible +@vindex appt-display-mode-line +@vindex appt-msg-window +@vindex appt-display-duration +@table @code +@item appt-message-warning-time +The time in minutes before an appointment that the reminder begins. The +default is 10 minutes. +@item appt-audible +If this is @code{t} (the default), Emacs rings the terminal bell for +appointment reminders. +@item appt-visible +If this is @code{t} (the default), Emacs displays the appointment +message in echo area. +@item appt-display-mode-line +If this is @code{t} (the default), Emacs displays the number of minutes +to the appointment on the mode line. +@item appt-msg-window +If this is @code{t} (the default), Emacs displays the appointment +message in another window. +@item appt-display-duration +The number of seconds an appointment message is displayed. The default +is 5 seconds. +@end table