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CALENDAR(1) DragonFly General Commands Manual CALENDAR(1)
calendar - reminder service
calendar [-A num] [-a] [-B num] [-d] [-F friday] [-f calendar_file]
[-H calendar_home] [-h] [-L latitude,longitude[,elevation]]
[-s category] [-T hh:mm[:ss]] [-t [[[CC]YY]MM]DD]
[-U +-hh[[:]mm]] [-W num]
The calendar utility processes calendar files and displays lines that
fall into the specified date range. On the day before a weekend
(normally Friday), events for the next three days are displayed.
The following options are available:
-A num Print lines from today and the next num days (forward, future).
-a Process the calendar files (~/.calendar/calendar) of all users
and mail the results to them. This requires super-user
-B num Print lines from today and the previous num days (backward,
-d Print debug messages. This flag may be repeated multiple times
to increase the verbosity.
Specify which day of the week is "Friday" (the day before the
weekend begins). The default is 5.
Use calendar_file as the default calendar file. If specified as
-, then read from standard input. Note that this flag cannot be
used together with the -a flag.
Use calendar_home as the calendar home directory. Note that this
flag cannot be used together with the -a flag.
-h Show the utility usage.
Specify the location for use in some calculations, such as the
current Sun and Moon positions and their rise and set times. The
latitude and longitude arguments are given in units of degrees,
which can be a decimal number or in the DMS format of
"[+-]d:m:s". The elevation argument is optional and is given in
units of meters. If not specified, the latitude and elevation
arguments are default to 0, while the longitude argument is
calculated from the adopted UTC offset (i.e., 15 degrees times
the UTC offset in hours).
Show information of the specified category, which can take the
chinese Show the Chinese calendar and the 24 solar terms (a.k.a.
Jieqi) in this year.
julian Show the Julian calendar.
moon Show Moon position, phases, rise and set times, and
lunar events in this year.
sun Show Sun position, rise and set times, and solar events
in this year.
Specify the time of day to use instead of the current system
time. This time is only used in determining the Sun and Moon
Act like the specified value is "today" instead of using the
current date. If YY is specified, but CC is not, a value for YY
between 69 and 99 results in a CC value of 19. Otherwise, a CC
value of 20 is used.
Specify the timezone with a UTC offset. If not specified, the
timezone of localtime is used.
-W num Print lines from today and the next num days (forward, future).
Similar to the -A option but ignore weekends when calculating the
number of days.
The calendar files are preprocessed by a limited subset of cpp(1)
internally, allowing the inclusion of shared calendar files. This
limited directive subset consists of #include, #ifndef, #endif, and
#define. If the calendar file to be included (via the #include
directive) is not referenced by a full pathname, calendar searches in its
home directory (~/.calendar or specified by the -H flag) first, then in
the /etc/calendar directory, and finally in the /usr/share/calendar
directory. Both the C-style comment (/* ... */) and C++-style comment
(// ...) are supported.
The default calendar used by the calendar utility is the "Gregorian
calendar". In addition, the following calendars are supported:
Julian The Julian calendar
Chinese The Chinese calendar
Specify "CALENDAR=<calendar>" in the calendar file to select the calendar
to use. The calendar will be reset to the default Gregorian calendar at
the end of the calendar file. When a non-default calendar is selected,
the matched events will be printed with a secondary date formatted in the
To handle calendars in national code table, specify "LANG=<locale>" in
the calendar file, before the national names being used. This setting
will also make the event date in this calendar file be formatted in
national names in the output. The locale change will be reset at the end
of the calendar file.
To handle the local name of sequences, specify them as "SEQUENCE=<first>
<second> <third> <fourth> <fifth> <last>" in the calendar file.
The names of the following special days are recognized:
Easter Catholic Easter.
Paskha Orthodox Easter.
Advent First Sunday of Advent.
NewMoon The lunar New Moon.
FullMoon The lunar Full Moon.
MarEquinox The solar equinox in March.
JunSolstice The solar solstice in June.
SepEquinox The solar equinox in September.
DecSolstice The solar solstice in December.
ChineseNewYear The first day of the Chinese year.
ChineseQingming The Chinese Qingming festival (a.k.a. Tomb-
ChineseJieqi The 24 solar terms (Jieqi) in Chinese calendar.
These names may be reassigned to their local names via an assignment like
"<name>=<local_name>" in the calendar file, and then the "<local_name>"
can also be used to specify the date.
Other lines should begin with a year (optional), month and day. They may
be entered in multiple formats, either numeric or as character strings.
If the proper locale is set (via "LANG=<locale>"), national month and
weekday names can be used as well. Additional rules are as follows:
* Two numbers default to the month followed by the day.
* A single asterisk (`*') matches every month.
* A day without a month matches that day of every week.
* A day of zero means the last day of previous month.
* The names of special days may be followed by a positive or
negative integer to represent the date offset, like: "Easter+3"
* A weekday may be followed by a sequence name ("First" ...
"Fifth", and "Last") to specify moving events, like "the last
Monday in April". Numeric sequence ("+-") can also be
* A date may be followed by an asterisk (`*') to indicate that it
is not fixed (i.e., changes from year to year).
* A date must be immediately followed by <tab> character(s), and
then followed by the event description. Lines without
containing a <tab> character are invalid and thus ignored.
* Lines starting with a <tab> character are treated as a
continuation of the previous line, allowing multiple-line
description of an event.
The supported date styles can vary with calendars. In the Gregorian
calendar, the following date styles are supported:
Date ::= Year . '/' . Month . '/' . DayOfMonth |
Year . ' ' . Month . ' ' . DayOfMonth |
Month . '/' . DayOfMonth |
Month . ' ' . DayOfMonth |
Month . '/' . DayOfWeek . Index |
Month . ' ' . DayOfWeek . Index |
MonthName . '/' . AllDays |
MonthName . ' ' . AllDays |
AllDays . '/' . MonthName |
AllDays . ' ' . MonthName |
AllMonths . '/' . DayOfMonth |
AllMonths . ' ' . DayOfMonth |
DayOfMonth . '/' . AllMonths |
DayOfMonth . ' ' . AllMonths |
DayOfMonth . '/' . Month |
DayOfMonth . ' ' . Month |
DayOfWeek . Index . '/' . MonthName |
DayOfWeek . Index . ' ' . MonthName |
DayOfWeek . Index
SpecialDay . Offset
Year ::= '0' ... '9' | '00' ... '09' | '10' ... '99' |
'100' ... '999' | '1000' ... '9999'
Month ::= MonthName | MonthNumber
MonthNumber ::= '0' ... '9' | '00' ... '09' | '10' ... '12'
MonthName ::= MonthNameShort | MonthNameLong
MonthNameLong ::= 'January' ... 'December'
MonthNameShort ::= 'Jan' ... 'Dec' | 'Jan.' ... 'Dec.'
DayOfWeek ::= DayOfWeekShort | DayOfWeekLong
DayOfWeekShort ::= 'Mon' ... 'Sun'
DayOfWeekLong ::= 'Monday' ... 'Sunday'
DayOfMonth ::= '0' ... '9' | '00' ... '09' | '10' ... '29' |
'30' ... '31'
AllMonths ::= '*'
AllDays ::= '*'
Index ::= '' | IndexName |
'+' . IndexNumber | '-' . IndexNumber
IndexName ::= 'First' | 'Second' | 'Third' | 'Fourth' |
'Fifth' | 'Last'
IndexNumber ::= '1' ... '5'
Offset ::= '' | '+' . OffsetNumber | '-' . OffsetNumber
OffsetNumber ::= '0' ... '9' | '00' ... '99' | '000' ... '299' |
'300' ... '359' | '360' ... '365'
SpecialDay ::= 'Easter' | 'Paskha' | 'Advent' |
'ChineseQingming' | 'ChineseJieqi' |
'NewMoon' | 'FullMoon' |
'MarEquinox' | 'SepEquinox' |
'JunSolstice' | 'DecSolstice'
Some possible calendar entries (<tab> characters highlighted as `\t'):
/* Include shared calendar files */
6/15\tJune 15 (if ambiguous, will default to month/day)
Jun. 15\tJune 15
15 June\tJune 15
15 *\t15th of every month
0 *\tLast day of every month
March/0\tLast day of February
2010/4/15\t15 April 2010
2020/11/03*\tU.S. Election Day ('*' indicates a movable event)
SatSecond\tSecond Saturday of every month
Apr/Mon\tEvery Monday in April
May Sun+2\tSecond Sunday in May (Muttertag)
04/SunLast\tLast Sunday in April,
\tSummer time in Europe // continuation of previous line
Ostern-2\tGood Friday (2 days before Easter)
NewMoon\tNew moon of every month
calendar The calendar file to find in current directory.
~/.calendar The default calendar home directory. A chdir(2)
is done into this directory if it exists.
~/.calendar/calendar The calendar file to use if no calendar file
exists in the current directory.
~/.calendar/nomail Do not send mail if this file exists.
/etc/calendar/default The system-wide default calendar file, which is
used if the ~/.calendar/calendar doesn't exist.
This fallback calendar file is ignored in the -a
The following calendar files are provided in /usr/share/calendar:
calendar.all File which includes all the calendar files.
calendar.australia Calendar of events in Australia.
calendar.birthday Births and deaths of famous (and not-so-famous)
calendar.brazilian Calendar of events in Brazil.
calendar.canada Canadian holidays.
calendar.chinese Calendar of events in China.
calendar.christian Christian holidays.
calendar.computer Days of special significance to computer people.
calendar.croatian Calendar of events in Croatia.
calendar.discord Discordian calendar (all rites reversed).
calendar.dragonfly DragonFly related events.
calendar.dutch Calendar of events in the Netherlands.
calendar.fictional Fantasy and fiction dates (mostly Load Of The
calendar.french Calendar of events in France.
calendar.german Calendar of events in Germany.
calendar.history Miscellaneous history.
calendar.holiday Other holidays, including the not-well-known,
obscure, and really obscure.
calendar.hungarian Calendar of events in Hungary.
calendar.judaic Jewish holidays. This calendar should be updated
yearly by the local system administrator so that
roving holidays are set correctly for the current
year. The entries for this calendar have been
obtained from the port deskutils/hebcal.
calendar.misc Miscellaneous events.
calendar.music Musical events, births, and deaths. Strongly
oriented toward rock 'n' roll and classical.
calendar.newzealand Calendar of events in New Zealand.
calendar.orthodox Orthodox holidays.
calendar.russian Russian calendar.
calendar.southafrica Calendar of events in South Africa.
calendar.space Aerospace and astronomical events.
calendar.uk Calendar of events in U.K.
calendar.ukrainian Calendar of events in Ukraine.
calendar.ushistory U.S. history.
calendar.usholiday U.S. holidays. This calendar should be updated
yearly by the local system administrator so that
roving holidays are set correctly for the current
calendar.world Includes all calendar files except for national
The calendar utility previously selected lines which had the correct date
anywhere in the line. This is no longer true: the date is only
recognized when it occurs at the beginning of a line.
at(1), cal(1), mail(1), cron(8)
Edward M. Reingold and Nachum Dershowitz, Calendrical Calculations: The
Ultimate Edition (4th Edition), Cambridge University Press, 2018, ISBN:
A calendar command appeared in Version 7 AT&T UNIX.
The calendar utility was significantly enhanced in FreeBSD 9.0 by Edwin
Groothuis <edwin@FreeBSD.org>, and was later rewritten to support
multiple calendars in DragonFly 5.9 by Aaron LI <firstname.lastname@example.org>.
The new and full moons are happening on the day indicated. They can
happen in the time period from the early morning to the late evening.
The adopted methods to calculate solar and lunar events are simplified
astronomical algorithms, so the accuracy of events is within several
minutes, provided that the precise location is specified. Druids and
Werewolves should double-check the start and end time of solar and lunar
The calendar internal preprocessor only recognizes #include, #ifndef,
#endif, and #define. Quoted or escaped comment marks are not supported
An event can repeat at most 100 times in the specified date range. The
most repeated event is an weekly event, so a maximum of 100 repeats
covers a date range of about 2 years. If more repeats of events are
needed, you're likely using calendar in the wrong way ;)
DragonFly 5.9-DEVELOPMENT September 14, 2020 DragonFly 5.9-DEVELOPMENT