NAME

calendar — reminder service

SYNOPSIS

calendar

[ -A num][ -a][ -B num][ -D moon|sun][ -d][ -F friday][ -f calendarfile][ -l longitude][ -t dd[ . mm[ . year]]][ -U UTC-offset][ -W num]

DESCRIPTION

The calendar utility checks the current directory for a file named calendar 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 of all users and mail the results to them. This requires super-user privileges.
-B num: Print lines from today and the previous num days (backward, past).
-D moon|sun: Print UTC offset, longitude and moon or sun information.
-d: Debug option: print current date information.
-F friday: Specify which day of the week is ``Friday'' (the day before the weekend begins). Default is 5.
-f calendarfile: Use calendarfile as the default calendar file.
-l longitude: Perform lunar and solar calculations from this longitude. If neither longitude nor UTC offset is specified, the calculations will be based on the difference between UTC time and localtime. If both are specified, UTC offset overrides longitude.
-t dd[ . mm[ . year]]: For test purposes only: set date directly to argument values.
-U UTC-offset: Perform lunar and solar calculations from this UTC offset. If neither UTC offset nor longitude is specified, the calculations will be based on the difference between UTC time and localtime. If both are specified, UTC offset overrides longitude.
-W num: Print lines from today and the next num days (forward, future). Ignore weekends when calculating the number of days.

FILE FORMAT

To handle calendars in your national code table you can specify “LANG=<locale_name>” in the calendar file as early as possible.

To handle the local name of sequences, you can specify them as: “SEQUENCE=<first> <second> <third> <fourth> <fifth> <last>” in the calendar file as early as possible.

The names of the following special days are recognized:

These names may be reassigned to their local names via an assignment like “Easter=Pasen” in the calendar file.

Other lines should begin with a month and day. They may be entered in almost any format, either numeric or as character strings. If the proper locale is set, national month and weekday names can be used. A single asterisk (``*'') matches every month. A day without a month matches that day of every week. A month without a day matches the first of that month. Two numbers default to the month followed by the day. Lines with leading tabs default to the last entered date, allowing multiple line specifications for a single date.

The names of the recognized special days may be followed by a positive or negative integer, like: “Easter+3” or “Paskha-4”.

Weekdays may be followed by ``-4'' ... ``+5'' (aliases for last, first, second, third, fourth) for moving events like ``the last Monday in April''.

By convention, dates followed by an asterisk are not fixed, i.e., change from year to year.

Day descriptions start after the first <tab> character in the line; if the line does not contain a <tab> character, it is not displayed. If the first character in the line is a <tab> character, it is treated as a continuation of the previous line.

The calendar file is preprocessed by a limited subset of cpp(1) internally, allowing the inclusion of shared files such as lists of company holidays or meetings. This limited subset consists of #include #ifndef #endif and #define. If the shared file is not referenced by a full pathname, calendar(1) searches in the current (or home) directory first, and then in the directory /usr/share/calendar. Empty lines and lines protected by the C commenting syntax ( /* ... */) are ignored.

Some possible calendar entries (<tab> characters highlighted by \t sequence)

LANG=C 
Easter=Ostern 
 
#include <calendar.usholiday> 
#include <calendar.birthday> 
 
6/15\tJune 15 (if ambiguous, will default to month/day). 
Jun. 15\tJune 15. 
15 June\tJune 15. 
Thursday\tEvery Thursday. 
June\tEvery June 1st. 
15 *\t15th of every month. 
2010/4/15\t15 April 2010 
 
May Sun+2\tsecond Sunday in May (Muttertag) 
04/SunLast\tlast Sunday in April, 
\tsummer time in Europe 
Easter\tEaster 
Ostern-2\tGood Friday (2 days before Easter) 
Paskha\tOrthodox Easter

FILES

The following default calendar files are provided in /usr/share/calendar:

COMPATIBILITY

The calendar program 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.

HISTORY

A calendar command appeared in Version 7 AT&T UNIX.

NOTES

Chinese New Year is calculated at 120 degrees east of Greenwich, which roughly corresponds with the east coast of China. For people west of China, this might result that the start of Chinese New Year and the day of the related new moon might differ.

The phases of the moon and the longitude of the sun are calculated against the local position which corresponds with 30 degrees times the time-difference towards Greenwich.

The new and full moons are happening on the day indicated: They might happen in the time period in the early night or in the late evening. It does not indicate that they are starting in the night on that date.

Because of minor differences between the output of the formulas used and other sources on the Internet, Druids and Werewolves should double-check the start and end time of solar and lunar events.

BUGS

The calendar internal cpp does not correctly do #ifndef and will discard the rest of the file if a #ifndef is triggered. It also has a maximum of 50 include file and/or 100 #defines and only recognises #include, #define and #ifndef.

There is no possibility to properly specify the local position needed for solar and lunar calculations.

YOS OPENSONAR