4.6.4 Free/Busy Component

Basic Definition | Formal Definition | Description| Example

Basic Definition

Component Name
VFREEBUSY
Purpose
Provide a grouping of component properties that describe either a request for free/busy time, describe a response to a request for free/busy time or describe a published set of busy time.

Formal Definition

A "VFREEBUSY" calendar component is defined by the
following notation:

  freebusyc  = "BEGIN" ":" "VFREEBUSY" CRLF
               fbprop
               "END" ":" "VFREEBUSY" CRLF

  fbprop     = *(

             ; the following are optional,
             ; but MUST NOT occur more than once

             contact / dtstart / dtend / duration / dtstamp /
             organizer / uid / url /

             ; the following are optional,
             ; and MAY occur more than once

             attendee / comment / freebusy / rstatus / x-prop

             )

Description

A "VFREEBUSY" calendar component is a grouping of component properties that represents either a request for, a reply to a request for free or busy time information or a published set of busy time information.

When used to request free/busy time information, the "ATTENDEE" property specifies the calendar users whose free/busy time is being requested; the "ORGANIZER" property specifies the calendar user who is requesting the free/busy time; the "DTSTART" and "DTEND" properties specify the window of time for which the free/busy time is being requested; the "UID" and "DTSTAMP" properties are specified to assist in proper sequencing of multiple free/busy time requests.

When used to reply to a request for free/busy time, the "ATTENDEE" property specifies the calendar user responding to the free/busy time request; the "ORGANIZER" property specifies the calendar user that originally requested the free/busy time; the "FREEBUSY" property specifies the free/busy time information (if it exists); and the "UID" and "DTSTAMP" properties are specified to assist in proper sequencing of multiple free/busy time replies.

When used to publish busy time, the "ORGANIZER" property specifies the calendar user associated with the published busy time; the "DTSTART" and "DTEND" properties specify an inclusive time window that surrounds the busy time information; the "FREEBUSY" property specifies the published busy time information; and the "DTSTAMP" property specifies the date/time that iCalendar object was created.

The "VFREEBUSY" calendar component cannot be nested within another calendar component. Multiple "VFREEBUSY" calendar components can be specified within an iCalendar object. This permits the grouping of Free/Busy information into logical collections, such as monthly groups of busy time information.

The "VFREEBUSY" calendar component is intended for use in iCalendar object methods involving requests for free time, requests for busy time, requests for both free and busy, and the associated replies.

Free/Busy information is represented with the "FREEBUSY" property. This property provides a terse representation of time periods. One or more "FREEBUSY" properties can be specified in the "VFREEBUSY" calendar component.

When present in a "VFREEBUSY" calendar component, the "DTSTART" and "DTEND" properties SHOULD be specified prior to any "FREEBUSY" properties. In a free time request, these properties can be used in combination with the "DURATION" property to represent a request for a duration of free time within a specified window of time.

The recurrence properties ("RRULE", "EXRULE", "RDATE", "EXDATE") are not permitted within a "VFREEBUSY" calendar component. Any recurring events are resolved into their individual busy time periods using the "FREEBUSY" property.

Example

The following is an example of a "VFREEBUSY" calendar
component used to request free or busy time information:

  BEGIN:VFREEBUSY
  ORGANIZER:MAILTO:jane_doe@host1.com
  ATTENDEE:MAILTO:john_public@host2.com
  DTSTART:19971015T050000Z
  DTEND:19971016T050000Z
  DTSTAMP:19970901T083000Z
  END:VFREEBUSY


The following is an example of a "VFREEBUSY" calendar component used
to reply to the request with busy time information:

  BEGIN:VFREEBUSY
  ORGANIZER:MAILTO:jane_doe@host1.com
  ATTENDEE:MAILTO:john_public@host2.com
  DTSTAMP:19970901T100000Z
  FREEBUSY;VALUE=PERIOD:19971015T050000Z/PT8H30M,
   19971015T160000Z/PT5H30M,19971015T223000Z/PT6H30M
  URL:http://host2.com/pub/busy/jpublic-01.ifb
  COMMENT:This iCalendar file contains busy time information for
    the next three months.
  END:VFREEBUSY

The following is an example of a "VFREEBUSY" calendar component used
to publish busy time information.

  BEGIN:VFREEBUSY
  ORGANIZER:jsmith@host.com
  DTSTART:19980313T141711Z
  DTEND:19980410T141711Z
  FREEBUSY:19980314T233000Z/19980315T003000Z
  FREEBUSY:19980316T153000Z/19980316T163000Z
  FREEBUSY:19980318T030000Z/19980318T040000Z
  URL:http://www.host.com/calendar/busytime/jsmith.ifb
  END:VFREEBUSY