xref: /freebsd/usr.bin/calendar/calendar.1 (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
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28.\"     @(#)calendar.1  8.1 (Berkeley) 6/29/93
29.\" $FreeBSD$
30.\"
31.Dd July 31, 2022
32.Dt CALENDAR 1
33.Os
34.Sh NAME
35.Nm calendar
36.Nd reminder service
37.Sh SYNOPSIS
38.Nm
39.Op Fl A Ar num
40.Op Fl a
41.Op Fl B Ar num
42.Op Fl D Ar moon|sun
43.Op Fl d
44.Op Fl F Ar friday
45.Op Fl f Ar calendarfile
46.Op Fl l Ar longitude
47.Oo
48.Bk -words
49.Fl t Ar dd Ns
50.Sm off
51.Op . Ar mm Op . Ar year
52.Sm on
53.Ek
54.Oc
55.Op Fl U Ar UTC-offset
56.Op Fl W Ar num
57.Sh DESCRIPTION
58The
59.Nm
60utility checks the current directory for a file named
61.Pa calendar
62and displays lines that fall into the specified date range.
63On the day before a weekend (normally Friday), events for the next
64three days are displayed.
65.Pp
66The following options are available:
67.Bl -tag -width Ds
68.It Fl A Ar num
69Print lines from today and the next
70.Ar num
71days (forward, future).
72.It Fl a
73Process the ``calendar'' files for users found in
74.Pa /etc/passwd
75and mail the results
76to them.
77This can result in multiple messages for specific files, since
78.Pa /etc/passwd
79does not require home directories to be unique.
80In particular, by default
81.Ar root ,
82.Ar toor
83and
84.Ar daemon
85share the same home directory.
86If this directory contains calendar information,
87.Nm
88will process the file three times.
89.Pp
90This option requires super-user privileges.
91.It Fl B Ar num
92Print lines from today and the previous
93.Ar num
94days (backward, past).
95.It Fl D Ar moon|sun
96Print UTC offset, longitude and moon or sun information.
97.It Fl d
98Debug option: print current date information.
99.It Fl F Ar friday
100Specify which day of the week is ``Friday'' (the day before the
101weekend begins).
102Default is 5.
103.It Fl f Pa calendarfile
104Use
105.Pa calendarfile
106as the default calendar file.
107.It Fl l Ar longitude
108Perform lunar and solar calculations from this longitude.
109If neither longitude nor UTC offset is specified, the calculations will
110be based on the difference between UTC time and localtime.
111If both are specified, UTC offset overrides longitude.
112.It Xo Fl t
113.Sm off
114.Ar dd
115.Op . Ar mm Op . Ar year
116.Sm on
117.Xc
118For test purposes only: set date directly to argument values.
119.It Fl U Ar UTC-offset
120Perform lunar and solar calculations from this UTC offset.
121If neither UTC offset nor longitude is specified, the calculations
122will be based on the difference between UTC time and localtime.
123If both are specified, UTC offset overrides longitude.
124.It Fl W Ar num
125Print lines from today and the next
126.Ar num
127days (forward, future).
128Ignore weekends when calculating the number of days.
129.El
130.Sh FILE FORMAT
131To handle calendars in your national code table you can specify
132.Dq LANG=<locale_name>
133in the calendar file as early as possible.
134.Pp
135To handle the local name of sequences, you can specify them as:
136.Dq SEQUENCE=<first> <second> <third> <fourth> <fifth> <last>
137in the calendar file as early as possible.
138.Pp
139The names of the following special days are recognized:
140.Bl -tag -width 123456789012345 -compact
141.It Easter
142Catholic Easter.
143.It Paskha
144Orthodox Easter.
145.It NewMoon
146The lunar New Moon.
147.It FullMoon
148The lunar Full Moon.
149.It MarEquinox
150The solar equinox in March.
151.It JunSolstice
152The solar solstice in June.
153.It SepEquinox
154The solar equinox in September.
155.It DecSolstice
156The solar solstice in December.
157.It ChineseNewYear
158The first day of the Chinese year.
159.El
160These names may be reassigned to their local names via an assignment
161like
162.Dq Easter=Pasen
163in the calendar file.
164.Pp
165Other lines should begin with a month and day.
166They may be entered in almost any format, either numeric or as character
167strings.
168If the proper locale is set, national month and weekday
169names can be used.
170A single asterisk (``*'') matches every month.
171A day without a month matches that day of every week.
172A month without a day matches the first of that month.
173Two numbers default to the month followed by the day.
174Lines with leading tabs default to the last entered date, allowing
175multiple line specifications for a single date.
176.Pp
177The names of the recognized special days may be followed by a
178positive or negative integer, like:
179.Dq Easter+3
180or
181.Dq Paskha-4 .
182.Pp
183Weekdays may be followed by ``-4'' ...\& ``+5'' (aliases for
184last, first, second, third, fourth) for moving events like
185``the last Monday in April''.
186.Pp
187By convention, dates followed by an asterisk are not fixed, i.e., change
188from year to year.
189.Pp
190Day descriptions start after the first <tab> character in the line;
191if the line does not contain a <tab> character, it is not displayed.
192If the first character in the line is a <tab> character, it is treated as
193a continuation of the previous line.
194.Pp
195The
196.Nm
197file is preprocessed by a limited subset of
198.Xr cpp 1
199internally, allowing the inclusion of shared files such as
200lists of company holidays or meetings.
201This limited subset consists of \fB#include\fR, \fB#define\fR,
202\fB#undef\fR, \fB#ifdef\fR, \fB#ifndef\fR, \fB#else\fR, \fB#warning\fR,
203and \fB#error\fR.
204.Pp
205Conditions can be nested and the consistency of opening and closing
206instructions is checked.
207Only the first word after #define is used as the name of the
208condition variable being defined.
209More than word following #ifdef, #ifndef, or #undef is considered a syntax
210error, since names cannot include white-space.
211Included files are parsed in a global scope with regard to the condition
212variables being defined or tested therein.
213All conditional blocks are implicitly closed at the end of a file,
214and missing #endif instructions are assumed to be present on implied
215succeeding lines.
216.Pp
217If the shared file is not referenced by a full pathname,
218.Nm
219searches in the current (or home) directory first, and then in the
220directory
221.Pa /usr/share/calendar .
222.Pp
223Blank lines and text protected by the C comment syntax
224.Ql /* ... */
225or
226.Ql //
227are ignored, but the latter only at the beginning of a line or after
228white space to allow for URLs in calendar entries.
229.Pp
230Some possible calendar entries (<tab> characters highlighted by
231\fB\et\fR sequence):
232.Bd -unfilled -offset indent
233LANG=C
234Easter=Ostern
235
236#include <calendar.usholiday>
237#include <calendar.birthday>
238
2396/15\fB\et\fRJune 15 (if ambiguous, will default to month/day).
240Jun. 15\fB\et\fRJune 15.
24115 June\fB\et\fRJune 15.
242Thursday\fB\et\fREvery Thursday.
243June\fB\et\fREvery June 1st.
24415 *\fB\et\fR15th of every month.
2452010/4/15\fB\et\fR15 April 2010
246
247May Sun+2\fB\et\fRsecond Sunday in May (Muttertag)
24804/SunLast\fB\et\fRlast Sunday in April,
249\fB\et\fRsummer time in Europe
250Easter\fB\et\fREaster
251Ostern-2\fB\et\fRGood Friday (2 days before Easter)
252Paskha\fB\et\fROrthodox Easter
253
254.Ed
255.Sh FILES
256.Bl -tag -width calendar.christian -compact
257.It Pa calendar
258file in current directory.
259.It Pa ~/.calendar
260.Pa calendar
261HOME directory.
262A chdir is done into this directory if it exists.
263.It Pa ~/.calendar/calendar
264calendar file to use if no calendar file exists in the current directory.
265.It Pa ~/.calendar/nomail
266do not send mail if this file exists.
267.It Pa /usr/share/calendar
268system wide location of calendar files provided as part of the base system.
269.It Pa /usr/local/share/calendar
270system wide location for calendar files provided by a port or package.
271.El
272.Pp
273The order of precedence in searches for a calendar file is:
274current directory, ~/.calendar, /usr/local/share/calendar, /usr/share/calendar.
275Files of similar names are ignored in lower precedence locations.
276.Pp
277The following default calendar files are provided by the
278deskutils/calendar-data port.
279.Pp
280.Bl -tag -width calendar.southafrica -compact
281.It Pa calendar.all
282File which includes all the default files.
283.It Pa calendar.australia
284Calendar of events in Australia.
285.It Pa calendar.birthday
286Births and deaths of famous (and not-so-famous) people.
287.It Pa calendar.christian
288Christian holidays.
289This calendar should be updated yearly by the local system administrator
290so that roving holidays are set correctly for the current year.
291.It Pa calendar.computer
292Days of special significance to computer people.
293.It Pa calendar.croatian
294Calendar of events in Croatia.
295.It Pa calendar.dutch
296Calendar of events in the Netherlands.
297.It Pa calendar.freebsd
298Birthdays of
299.Fx
300committers.
301.It Pa calendar.french
302Calendar of events in France.
303.It Pa calendar.german
304Calendar of events in Germany.
305.It Pa calendar.history
306Everything else, mostly U.S.\& historical events.
307.It Pa calendar.holiday
308Other holidays, including the not-well-known, obscure, and
309.Em really
310obscure.
311.It Pa calendar.judaic
312Jewish holidays.
313The entries for this calendar have been obtained from the
314deskutils/hebcal port.
315.It Pa calendar.music
316Musical events, births, and deaths.
317Strongly oriented toward rock 'n' roll.
318.It Pa calendar.newzealand
319Calendar of events in New Zealand.
320.It Pa calendar.russian
321Russian calendar.
322.It Pa calendar.southafrica
323Calendar of events in South Africa.
324.It Pa calendar.usholiday
325U.S.\& holidays.
326This calendar should be updated yearly by the local system administrator
327so that roving holidays are set correctly for the current year.
328.It Pa calendar.world
329Includes all calendar files except for national files.
330.El
331.Sh COMPATIBILITY
332The
333.Nm
334program previously selected lines which had the correct date anywhere
335in the line.
336This is no longer true, the date is only recognized when it occurs
337at the beginning of a line.
338.Sh SEE ALSO
339.Xr at 1 ,
340.Xr mail 1 ,
341.Xr cron 8
342.Sh HISTORY
343A
344.Nm
345command appeared in
346.At v7 .
347.Sh NOTES
348Chinese New Year is calculated at 120 degrees east of Greenwich,
349which roughly corresponds with the east coast of China.
350For people west of China, this might result that the start of Chinese
351New Year and the day of the related new moon might differ.
352.Pp
353The phases of the moon and the longitude of the sun are calculated
354against the local position which corresponds with 30 degrees times
355the time-difference towards Greenwich.
356.Pp
357The new and full moons are happening on the day indicated: They
358might happen in the time period in the early night or in the late
359evening.
360It does not indicate that they are starting in the night on that date.
361.Pp
362Because of minor differences between the output of the formulas
363used and other sources on the Internet, Druids and Werewolves should
364double-check the start and end time of solar and lunar events.
365.Sh BUGS
366The
367.Nm
368does only recognise the cpp directives #include, #define, #ifdef,
369#ifndef and #else.
370It supports nested conditions, but does not perform any validation
371on the correct use and nesting of conditions.
372#endif without prior #ifdef or #define is ignored and #else outside
373a conditional section skips input lines up to the next #endif.
374.Pp
375There is no possibility to properly specify the local position
376needed for solar and lunar calculations.
377