University of Natural Resources and Life Sciences (BOKU)
Institute of Computational Biology

Calendar Plugin

The CalendarPlugin handles the macro %CALENDAR% that inserts a monthly calendar in the page. Multiple topics can be specified as the source of the events, and these can be in any web. The calendar marks dates corresponding to the events. Events can be listed literally in the topics, or can be taken from the results of macro expansions (such as %SEARCH).

NOTE since release 2.000, the plugin now respects access controls on topics containing events. You must have VIEW permission on these topics to be able to see the events they contain.

Also since 2.000, preferences settings in this topic are no longer read. Please define preferences as non-plugin preference settings instead.

Syntax Rules

You type you get
%CALENDAR% a monthly calendar for the current month/year, with events taken from the current topic
%CALENDAR{<attributes>}% is the full syntax

Attributes recognized

Attribute Meaning Default
year="yyyy" The year Current year
year="+yy" or "-yy" Relative year Current year
month="mm" The month Current month
month="+mm" or "-mm" relative month Current month
gmtoffset="+/-hh" Timezone expressed as number of hours offset from GMT Server timezone
topic="TopicName" Topic containing events The topic containing the tag
topic="Web.TopicName1, Web.TopicName2" Topics containing events The topics containing the events. You must have VIEW access to these topics, or the events therein will be ignored.
web="Webname" Web containing the event topic The current web
lang="language" Language: First few characters of "English", "Français", "Deutsch", "Español", "Português", "Nederlands", "Italiano", "Norsk", "Svenska", "Dansk", "suomi", "Magyar", "polski", "Romaneste" "English"
daynames="Mon¦Tue¦..." Custom day names "Monday¦Tuesday¦Wednesday¦Thursday¦
header="..." Text at the top of the calendar; use $m for current month, $y for year Current month and year
weekstartsonmonday="1" or "0" Flag to start week on Monday "0" (Sunday)
showdatenumbers="0" Show day numbers 1...31 in date cells. Note that showdatenumbers=1 means that HTML::CalendarMonthSimple will add the date numbers to the cells. If showdatenumbers=0, then the plugin adds the date numbers. The result of this is that a calendar will always show the date numbers. "0" (except with aslist="1", see below)
showweekdayheaders="1" Show the weekday headers "0"
weekdayheadersbig="0" If enabled, show weekday headers in bold cell headings "1"
cellalignment="left" Horizontal cell alignment of day cells: "left", "center", "right", "justify", "char" "center"
vcellalignment="middle" Vertical cell alignment of day cells: "top", "middle", "bottom", "baseline" "top"
cellheight="n" Height in pixels of each cell in the calendar Minimum height needed
format="..." How to highlight a date. NOTE make sure you use $old to denote the date output, otherwise you may only see one event per day. See Event Formatting below
width="n" or "n%" Width of calendar table in pixels or percent Minimum width needed
border="n" Border width of calendar table "1"
nowrap="1" or "0" Prevent cell content from wrapping "0"
bgcolor="#nnnn" Default background color of all cells unless redefined by other color settings below (use an HTML color-code like "#000000" as defined in StandardColors) white
contentcolor="#nnnn" Default content color of all cells unless redefined black
headercolor="#nnnn" Background color of the Month+Year header The web bgcolor
headercontentcolor="#nnnn" Content color of the Month+Year header contentcolor setting
weekdayheadercolor="#nnnn" Background color of weekdays' headers bgcolor setting
Content color of weekdays' headers contentcolor setting
weekendheadercolor="#nnnn" Background color of weekends' headers bgcolor setting
Content color of weekends' headers contentcolor setting
weekdaycolor="#nnnn" Background color of weekday cells bgcolor setting
weekdaycontentcolor="#nnnn" Content color of weekday cells contentcolor setting
weekendcolor="#nnnn" Background of weekend cells light gray
weekendcontentcolor="#nnnn" Content color of weekend cells contentcolor setting
todaycolor="#nnnn" Background of today's cell The web bgcolor
todaycontentcolor="#nnnn" Content color of today's cell contentcolor setting
and other attributes of HTML::CalendarMonthSimple
aslist Controls whether events displayed in calendar style (aslist=0) or list style (aslist=1). Note that specifying aslist=1 forces showdatenumbers=1 and defaults to show only one day's events (see day and days). This is done to ensure that the date number is formatted according to datenumberformat and that only the days that have an event are listed. 0
day Specifies the first day to show. Only valid if aslist=1. 1
days Specifies how many days of calendar data to list. Only valid if aslist=1. 1
months Specifies how many months of calendars to display. Only valid if aslist=0. 1
datenumberformat Specifies formatting for the date number in each cell. The formatting codes accepted are the same as those for the %GMTIME% variable. '$day' (if aslist=0)
' * $day $mon $year' (if aslist=1)
todaydatenumberformat Specifies formatting for the date number for the current day (today) in the calendar. The formatting codes accepted are the same as those for the %GMTIME% variable. datenumberformat
multidayformat Specifies formatting of the description for multi-day events. See Multi-Day Event Formatting for details. $description
tableclass css class given to the outer table calendar $month $year
cellclass css class given to each day's element day $day $month $year
weekdaycellclass css class given to weekdays in the showweekdayheaders weekday
weekendcellclass css class given to weekendin the showweekdayheaders weekend
todaycellclass css class given to today's element (inaddition to cellclass) today
headerclass css class given to the header calendarHeader
eventbgcolor Background color Event, when have a event in calendar for default is undef, you have to put some color

Event Syntax

Events are defined by bullets with the following syntax:

Event type Syntax Example
Single:    * dd MMM yyyy - description 09 Dec 2002 - Expo
Interval:    * dd MMM yyyy - dd MMM yyyy - description 02 Feb 2002 - 04 Feb 2002 - Vacation
Yearly:    * dd MMM - description 05 Jun - Every 5th of June
   * w DDD MMM - description 2 Tue Mar - Every 2nd Tuesday of March
   * L DDD MMM - description L Mon May - The last Monday of May
   * A dd MMM yyyy - description A 20 Jul 1969 - First moon landing
This style will mark anniversaries of an event that occurred on the given date. The description will have " (x)" appended to it, where "x" indicates how many years since the occurence of the first date. The first date is not annotated.
Monthly:    * w DDD - description 1 Fri - Every 1st Friday of the month
   * L DDD - description L Mon - The last Monday of each month
   * dd - description 14 - The 14th of every month
Weekly:    * E DDD - description E Wed - Every Wednesday
   * E DDD dd MMM yyyy - description E Wed 27 Jan 2005 - Every Wednesday Starting 27 Jan 2005
   * E DDD dd MMM yyyy - dd MMM yyyy - description E Wed 1 Jan 2005 - 27 Jan 2005 - Every Wednesday from 1 Jan 2005 through 27 Jan 2005 (inclusive)
Periodic:    * En dd MMM yyyy - description E3 02 Dec 2002 - Every three days starting 02 Dec 2002
   * En dd MMM yyyy - dd MMM yyyy - description E3 12 Apr 2005 - 31 Dec 2005 - Every three days from 12 Apr 2005 through 31 Dec 2005 (inclusive)
Exception: Insert the following between the above syntax and the description:
X { dd MMM yyyy, dd MMM yyyy - dd MMM yyyy }
1 Fri X { 01 Dec 2002, 06 Dec 2002 - 14 Dec 2002 } - Every first Friday except on the 01 Dec 2002 and between 06 Dec 2002 and 14 Dec 2002

Event formatting

For a table-style calendar, each day which has one or more events will have a list of the descriptions of those events. Each event description will be set in a small font. In other words, format is:
$old<br /><small>$description</small>

For a list-style calendar, if an event falls in the selected time period, then it is displayed (by default) as a bullet item with the date as dd Mmm yyyy In other words, datenumberformat is:
   * $day $mon $year
and format is:
$old - $description

This displays the events in a form very similar to that in which they are specified (although specific to a particular date).

Multi-Day Event Formatting

The multidayformat option allows the description of each day of a multiday event to be displayed differently. This could be used to visually or textually annotate the description to indicate continuance from or to other days.

The option consists of a comma separated list of formats for each type of day in a multiday event:

first, middle, last, middle-unseen, last-unseen


  • first is the format used when the first day of the event is displayed
  • middle is the format used when the day being displayed is not the first or last day
  • last is the format used when the last day of the event is displayed
  • middle-unseen is the format used when the day being displayed is not the first or last day of the event, but the preceding days of the event have not been displayed. For example, if an event runs from 29 Apr to 2 May and a May calendar is being displayed, then this format would be used for 1 May.
  • last-unseen is the format used when the day being displayed is the last day of the event, but the preceding days of the event have not been displayed. For example, if an event runs from 29 Apr to 1 May and a May calendar is being displayed, then this format would be used for 1 May. Note that in the previous example (event from 29 Apr to 2 May), this format would not be used for a May calendar because the event was "seen" on 1 May; so, the last format would be used for 2 May.

Within each format, date information for the current day can be substituted using the same format codes as accepted by %GMTIME%. An extension to these codes allows the date of the first and/or last day of the event to also be rendered.

  • $first(format) will render the first date of the event according to format, where format is, again, a string of codes acceptable to %GMTIME%.
  • $last(format) will render the last date of the event in the way just described for $first()

Missing formats will be filled in as follows:

  • middle will be set to first
  • last will be set to middle
  • middle-unseen will be set to middle
  • last-unseen will be set to last

Missing formats are different from empty formats. For example,

multidayformat="$description (until $last($day $month)),,"

specifies an empty format for middle and last. The result of this is that only the first day will be shown. Note that since an unspecified middle-unseen is set from the (empty) middle format, an event that begins prior to the calendar being displayed but ending in the current calendar will not be displayed. In contrast, multidayformat="$description" will simply display the description for each day of the event; all days (within the scope of the calendar) will be displayed.

The default format is to simply display the description of the event.

Other sources of calendars

You can also use the Foswiki:Extensions.CalDAVPlugin to recover calendars from a CalDAV server.


You type:You get:If correctly installed:
A list of Events is just a bullet list like this:
  • 2 Feb - Andrea's birthday
  • A 7 Mar 1966 - Nicoletta's birthday
  • 29 May 1996 - Maria Teresa is born!
  • 29 Sep 1998 - Davide is born!

%CALENDAR{month="2" year="2002" bgcolor="cyan"}% %CALENDAR{month="3" year="2002" showweekdayheaders="1"}%

February 2002
          01 02
Andrea's birthday
03 04 05 06 07 08 09
10 11 12 13 14 15 16
17 18 19 20 21 22 23
24 25 26 27 28    

March 2002
Sunday Monday Tuesday Wednesday Thursday Friday Saturday
          01 02
03 04 05 06 07
Nicoletta's birthday (36)
08 09
10 11 12 13 14 15 16
17 18 19 20 21 22 23
24 25 26 27 28 29 30

February 2002
          01 02
Andrea's birthday
03 04 05 06 07 08 09
10 11 12 13 14 15 16
17 18 19 20 21 22 23
24 25 26 27 28    

March 2002
Sunday Monday Tuesday Wednesday Thursday Friday Saturday
          01 02
03 04 05 06 07
Nicoletta's birthday (36)
08 09
10 11 12 13 14 15 16
17 18 19 20 21 22 23
24 25 26 27 28 29 30


Any of the recognized CALENDAR{} macro attributes can be defaulted using preferences. These preferences all start with CALENDARPLUGIN_ and end with the upper case name of the attribute. For example, the following affect only Calendars on this topic:
Preferences can be set at the site, web, topic or user level. See PreferenceSettings for more information.

Note: this is different from TWiki CalendarPlugin for significant performance reasons, and because in foswiki, its prefferable not to modify topics in the System web.

Installation Instructions

You do not need to install anything in the browser to use this extension. The following instructions are for the administrator who installs the extension on the server.

Open configure, and open the "Extensions" section. Use "Find More Extensions" to get a list of available extensions. Select "Install".

If you have any problems, or if the extension isn't available in configure, then you can still install manually from the command-line. See for more help.

You should see two calendars near the Event list above and a current month calendar below (using css style section inline):
June 2024
02 03 04 05 06 07 08
09 10 11 12 13 14 15
16 17 18 19 20 21 22
23 24 25 26 27 28 29


Change History:  
2.100 (1 Sep 2015): Foswiki:Tasks.Item2038: Preserve header colors across multiple months.
Foswiki:Tasks.Item10135: Don't omit events outside of STARTINCLUDE/STOPINCLUDE blocks
Foswiki:Tasks.Item11202: Modernize CalendarPlugin (phase 1)
Update copyright, Eliminate Subversion macros, Remove high characters from plugin topic. Foswiki:Main.GeorgeClark
2.001 (26 Oct 2011): Foswiki:Tasks.Item11202: created unit tests! rewrote the parse code to make it testable - Foswiki:Main.SvenDowideit
2.000 (30 Jun 2010): Foswiki:Tasks.Item1841: Foswiki:Tasks.Item8421: Foswiki:Tasks.Item1546: added support for macro expansions to provide the event lists. This allows other plugins to generate data sources e.g. by including calendars from e.g. CalDAV. Restructured for maintenance and performance. Foswiki:Tasks.Item9231: Added topic permission checking. Crawford Currie
12 Aug 2009: Foswiki:Main.MarcelloBontempoSalgueiro: add eventbgcolor attribute for background color when day have a event
09 March 2009: Foswiki:Main.SvenDowideit: add day attribute for aslist rendering so users can select a start day
28 Feb 2009: Foswiki:Main.SvenDowideit: add css classes and parameters so that we're not so ugly anymore
10 Feb 2009: Foswiki:Main.SvenDowideit: port to Foswiki
1.020: TWiki:Main.DavidBright: Bug fix from TWiki:Main.MarcLangheinrich for multiday events that were not properly displayed because the first day occurred in the current month, but before the first day included in the list.
1.019: TWiki:Main.DavidBright: Added support for monthly repeaters specified as "L Fri" (last Friday in all months).
1.018: TWiki:Main.DavidBright: Added capability to display multiple months in one call, display events in a list, and provided for more extensive formatting of date and description of events.
1.017: TWiki:Main.DanielRohde: Added start and end date support for periodic repeaters; Added initlang patch by TWiki:Main.JensKloecker; Changed 'my' to 'local' so exceptions working again; Removed fetchxmap debug message; Fixed illegal date bug; Allowed month abbreviations in month attribute
1.016: TWiki:Main/DavidBright: Added support for anniversary events; changed "our" to "my" in module to support perl versions prior to 5.6.0
1.015: TWiki:Main.PatriceFournier: Added back support for preview showing unsaved events; Two loop fixes from TWiki:Main.DanielRohde
1.014: TWiki:Main.NathanKerr: Added start and end date support for weekly repeaters
1.013: TWiki:Main.MartinCleaver: Added multiple topic=web.topic parameters
1.012: TWiki:Main/PeterThoeny: Added missing doc of gmtoffset parameter (was deleted in 1.011)
1.011: TWiki:Main/PeterThoeny: Fixed deep recursion bug; preview shows now unsaved events; performance and resource improvements; documented most of HTML::CalendarMonthSimple attributes; TWiki:Main/PaulineCheung: Fixed uninitialized value in join
1.010: TWiki:Main/DanBoitnott: Fixed variable conflict in timezone code
1.009: TWiki:Main/DanBoitnott: Added ability to have event topics in other webs
1.008: TWiki:Main/AnthonPang: Added daynames attribute; TWiki:Main/JensKloecker: Added lang attribute; TWiki:Main/DanBoitnott: Added yearly, monthly, weekly, and periodic events and exceptions
1.006: TWiki:Main/DanBoitnott: Added monthly date support
1.005: TWiki:Main/AkimDemaille: handle date intervals (thanks!)
1.004: uses only HTML::CalendarMonthSimple, ISO dates, all possible settings, fixed month bug
1.003: introducing HTML::CalendarMonthSimple
1.002: TWiki:Main/ChristianSchultze: highlight today, relative month/year and debugging (thanks!)
1.001: delayed load of used packages
1.000: first release using only HTML::CalendarMonth
20 Jun 2024 - 03:30 Foswiki v2.0.2