icalendar.cal.availability module#

This implementes the VAVAILABILITY component.

This is specified in RFC 7953.

class icalendar.cal.availability.Availability(*args, **kwargs)[source]#

Bases: Component

VAVAILABILITY component from RFC 7953.

This provides a grouping of component properties and subcomponents that describe the availability associated with a calendar user.

Description:

A "VAVAILABILITY" component indicates a period of time within which availability information is provided. A "VAVAILABILITY" component can specify a start time and an end time or duration. If "DTSTART" is not present, then the start time is unbounded. If "DTEND" or "DURATION" are not present, then the end time is unbounded. Within the specified time period, availability defaults to a free-busy type of "BUSY-UNAVAILABLE" (see Section 3.2), except for any time periods corresponding to "AVAILABLE" subcomponents.

"AVAILABLE" subcomponents are used to indicate periods of free time within the time range of the enclosing "VAVAILABILITY" component. "AVAILABLE" subcomponents MAY include recurrence properties to specify recurring periods of time, which can be overridden using normal iCalendar recurrence behavior (i.e., use of the "RECURRENCE-ID" property).

If specified, the "DTSTART" and "DTEND" properties in "VAVAILABILITY" components and "AVAILABLE" subcomponents MUST be "DATE-TIME" values specified as either the date with UTC time or the date with local time and a time zone reference.

The iCalendar object containing the "VAVAILABILITY" component MUST contain appropriate "VTIMEZONE" components corresponding to each unique "TZID" parameter value used in any DATE-TIME properties in all components, unless [RFC7809] is in effect.

When used to publish available time, the "ORGANIZER" property specifies the calendar user associated with the published available time.

If the "PRIORITY" property is specified in "VAVAILABILITY" components, it is used to determine how that component is combined with other "VAVAILABILITY" components. See Section 4.

Other calendar properties MAY be specified in "VAVAILABILITY" or "AVAILABLE" components and are considered attributes of the marked block of time. Their usage is application specific. For example, the "LOCATION" property might be used to indicate that a person is available in one location for part of the week and a different location for another part of the week (but see Section 9 for when it is appropriate to add additional data like this).

Example

The following is an example of a "VAVAILABILITY" calendar component used to represent the availability of a user, always available Monday through Friday, 9:00 am to 5:00 pm in the America/Montreal time zone:

BEGIN:VAVAILABILITY
ORGANIZER:mailto:bernard@example.com
UID:0428C7D2-688E-4D2E-AC52-CD112E2469DF
DTSTAMP:20111005T133225Z
BEGIN:AVAILABLE
UID:34EDA59B-6BB1-4E94-A66C-64999089C0AF
SUMMARY:Monday to Friday from 9:00 to 17:00
DTSTART;TZID=America/Montreal:20111002T090000
DTEND;TZID=America/Montreal:20111002T170000
RRULE:FREQ=WEEKLY;BYDAY=MO,TU,WE,TH,FR
END:AVAILABLE
END:VAVAILABILITY

You can get the same example from example():

The following is an example of a "VAVAILABILITY" calendar component used to represent the availability of a user available Monday through Thursday, 9:00 am to 5:00 pm, at the main office, and Friday, 9:00 am to 12:00 pm, in the branch office in the America/Montreal time zone between October 2nd and December 2nd 2011:

BEGIN:VAVAILABILITY
ORGANIZER:mailto:bernard@example.com
UID:84D0F948-7FC6-4C1D-BBF3-BA9827B424B5
DTSTAMP:20111005T133225Z
DTSTART;TZID=America/Montreal:20111002T000000
DTEND;TZID=America/Montreal:20111202T000000
BEGIN:AVAILABLE
UID:7B33093A-7F98-4EED-B381-A5652530F04D
SUMMARY:Monday to Thursday from 9:00 to 17:00
DTSTART;TZID=America/Montreal:20111002T090000
DTEND;TZID=America/Montreal:20111002T170000
RRULE:FREQ=WEEKLY;BYDAY=MO,TU,WE,TH
LOCATION:Main Office
END:AVAILABLE
BEGIN:AVAILABLE
UID:DF39DC9E-D8C3-492F-9101-0434E8FC1896
SUMMARY:Friday from 9:00 to 12:00
DTSTART;TZID=America/Montreal:20111006T090000
DTEND;TZID=America/Montreal:20111006T120000
RRULE:FREQ=WEEKLY
LOCATION:Branch Office
END:AVAILABLE
END:VAVAILABILITY

For more examples, have a look at RFC 5545.

Set keys to upper for initial dict.

property CREATED: datetime | None#

The CREATED property. datetime in UTC

All values will be converted to a datetime in UTC.

CREATED specifies the date and time that the calendar information was created by the calendar user agent in the calendar store.

Conformance:

The property can be specified once in "VEVENT", "VTODO", or "VJOURNAL" calendar components. The value MUST be specified as a date with UTC time.

property DTEND: datetime | None#

The DTEND property. datetime in UTC

All values will be converted to a datetime in UTC. Start of the component.

This is almost the same as Event.DTEND with one exception: The values MUST have a timezone and DATE is not allowed.

Description:

RFC 7953: If specified, the "DTSTART" and "DTEND" properties in "VAVAILABILITY" components and "AVAILABLE" subcomponents MUST be "DATE-TIME" values specified as either the date with UTC time or the date with local time and a time zone reference.

property DTSTAMP: datetime | None#

The DTSTAMP property. datetime in UTC

All values will be converted to a datetime in UTC. RFC 5545:

Conformance: This property MUST be included in the "VEVENT", "VTODO", "VJOURNAL", or "VFREEBUSY" calendar components.

Description: In the case of an iCalendar object that specifies a "METHOD" property, this property specifies the date and time that the instance of the iCalendar object was created. In the case of an iCalendar object that doesn't specify a "METHOD" property, this property specifies the date and time that the information associated with the calendar component was last revised in the calendar store.

The value MUST be specified in the UTC time format.

In the case of an iCalendar object that doesn't specify a "METHOD" property, this property is equivalent to the "LAST-MODIFIED" property.

property DTSTART: datetime | None#

The DTSTART property. datetime in UTC

All values will be converted to a datetime in UTC. Start of the component.

This is almost the same as Event.DTSTART with one exception: The values MUST have a timezone and DATE is not allowed.

Description:

RFC 7953: If specified, the "DTSTART" and "DTEND" properties in "VAVAILABILITY" components and "AVAILABLE" subcomponents MUST be "DATE-TIME" values specified as either the date with UTC time or the date with local time and a time zone reference.

property DURATION: timedelta | None#

The DURATION property.

The "DTSTART" property for a "Availability" specifies the inclusive start of the Availability. The "DURATION" property in conjunction with the DTSTART property for a "Availability" calendar component specifies the non-inclusive end of the event.

If you would like to calculate the duration of a Availability, do not use this. Instead use the duration property (lower case).

property LAST_MODIFIED: datetime | None#

The LAST-MODIFIED property. datetime in UTC

All values will be converted to a datetime in UTC. RFC 5545:

Purpose: This property specifies the date and time that the information associated with the calendar component was last revised in the calendar store.

Note: This is analogous to the modification date and time for a file in the file system.

Conformance: This property can be specified in the "VEVENT", "VTODO", "VJOURNAL", or "VTIMEZONE" calendar components.

add(name, value, parameters=None, encode=True)#

Add a property.

Parameters:
  • name (string) – Name of the property.

  • value (Python native type or icalendar property type.) – Value of the property. Either of a basic Python type of any of the icalendar's own property types.

  • parameters (Dictionary) – Property parameter dictionary for the value. Only available, if encode is set to True.

  • encode (Boolean) – True, if the value should be encoded to one of icalendar's own property types (Fallback is "vText") or False, if not.

Returns:

None

add_component(component)#

Add a subcomponent to this component.

property available: list[Available]#

All VAVAILABLE sub-components.

This is a shortcut to get all VAVAILABLE sub-components. Modifications do not change the calendar. Use Component.add_component().

property busy_type: StrEnum#

BUSYTYPE specifies the default busy time type.

Returns:

icalendar.enums.BUSYTYPE

Description:

This property is used to specify the default busy time type. The values correspond to those used by the FBTYPE" parameter used on a "FREEBUSY" property, with the exception that the "FREE" value is not used in this property. If not specified on a component that allows this property, the default is "BUSY- UNAVAILABLE".

canonical_order = ('DTSTART', 'DTEND', 'DURATION', 'DTSTAMP', 'UID', 'SEQUENCE', 'SUMMARY', 'DESCRIPTION', 'ORGANIZER')#
property categories: list[str]#

This property defines the categories for a component.

Property Parameters:

IANA, non-standard, and language property parameters can be specified on this property.

Conformance:

The property can be specified within "VEVENT", "VTODO", or "VJOURNAL" calendar components. Since RFC 7986 it can also be defined on a "VCALENDAR" component.

Description:

This property is used to specify categories or subtypes of the calendar component. The categories are useful in searching for a calendar component of a particular type and category. Within the "VEVENT", "VTODO", or "VJOURNAL" calendar components, more than one category can be specified as a COMMA-separated list of categories.

Example

Below, we add the categories to an event:

>>> from icalendar import Event
>>> event = Event()
>>> event.categories = ["Work", "Meeting"]
>>> print(event.to_ical())
BEGIN:VEVENT
CATEGORIES:Work,Meeting
END:VEVENT
>>> event.categories.append("Lecture")
>>> event.categories == ["Work", "Meeting", "Lecture"]
True

Note

At present, we do not take the LANGUAGE parameter into account.

See also

Component.concepts

property classification: StrEnum#

CLASS specifies the class of the calendar component.

Returns:

icalendar.enums.CLASS

Description:

An access classification is only one component of the general security system within a calendar application. It provides a method of capturing the scope of the access the calendar owner intends for information within an individual calendar entry. The access classification of an individual iCalendar component is useful when measured along with the other security components of a calendar system (e.g., calendar user authentication, authorization, access rights, access role, etc.). Hence, the semantics of the individual access classifications cannot be completely defined by this memo alone. Additionally, due to the "blind" nature of most exchange processes using this memo, these access classifications cannot serve as an enforcement statement for a system receiving an iCalendar object. Rather, they provide a method for capturing the intention of the calendar owner for the access to the calendar component. If not specified in a component that allows this property, the default value is PUBLIC. Applications MUST treat x-name and iana-token values they don't recognize the same way as they would the PRIVATE value.

clear()#

Remove all items from ordered dict.

property comments: list[str]#

COMMENT is used to specify a comment to the calendar user.

Purpose:

This property specifies non-processing information intended to provide a comment to the calendar user.

Conformance:

In RFC 5545, this property can be specified multiple times in "VEVENT", "VTODO", "VJOURNAL", and "VFREEBUSY" calendar components as well as in the "STANDARD" and "DAYLIGHT" sub-components. In RFC 7953, this property can be specified multiple times in "VAVAILABILITY" and "VAVAILABLE".

Property Parameters:

IANA, non-standard, alternate text representation, and language property parameters can be specified on this property.

property concepts: list[vUri]#

CONCEPT

Purpose:

CONCEPT defines the formal categories for a calendar component.

Conformance:

Since RFC 9253, this property can be specified zero or more times in any iCalendar component.

Description:

This property is used to specify formal categories or classifications of the calendar component. The values are useful in searching for a calendar component of a particular type and category.

This categorization is distinct from the more informal "tagging" of components provided by the existing CATEGORIES property. It is expected that the value of the CONCEPT property will reference an external resource that provides information about the categorization.

In addition, a structured URI value allows for hierarchical categorization of events.

Possible category resources are the various proprietary systems, for example, the Library of Congress, or an open source of categorization data.

Examples

The following is an example of this property. It points to a server acting as the source for the calendar object.

CONCEPT:https://example.com/event-types/arts/music

See also

Component.categories

property contacts: list[str]#

Contact information associated with the calendar component.

Purpose:

This property is used to represent contact information or alternately a reference to contact information associated with the calendar component.

Property Parameters:

IANA, non-standard, alternate text representation, and language property parameters can be specified on this property.

Conformance:

In RFC 5545, this property can be specified in a "VEVENT", "VTODO", "VJOURNAL", or "VFREEBUSY" calendar component. In RFC 7953, this property can be specified in a "VAVAILABILITY" amd "VAVAILABLE" calendar component.

Description:

The property value consists of textual contact information. An alternative representation for the property value can also be specified that refers to a URI pointing to an alternate form, such as a vCard RFC 2426, for the contact information.

Example

The following is an example of this property referencing textual contact information:

CONTACT:Jim Dolittle\, ABC Industries\, +1-919-555-1234

The following is an example of this property with an alternate representation of an LDAP URI to a directory entry containing the contact information:

CONTACT;ALTREP="ldap://example.com:6666/o=ABC%20Industries\,
c=US???(cn=Jim%20Dolittle)":Jim Dolittle\, ABC Industries\,
+1-919-555-1234

The following is an example of this property with an alternate representation of a MIME body part containing the contact information, such as a vCard RFC 2426 embedded in a text/ directory media type RFC 2425:

CONTACT;ALTREP="CID:part3.msg970930T083000SILVER@example.com":
 Jim Dolittle\, ABC Industries\, +1-919-555-1234

The following is an example of this property referencing a network resource, such as a vCard RFC 2426 object containing the contact information:

CONTACT;ALTREP="http://example.com/pdi/jdoe.vcf":Jim
 Dolittle\, ABC Industries\, +1-919-555-1234
content_line(name, value, sorted=True)#

Returns property as content line.

content_lines(sorted=True)#

Converts the Component and subcomponents into content lines.

copy(recursive=False)#

Copy the component.

Parameters:

recursive (bool) – If True, this creates copies of the component, its subcomponents, and all its properties. If False, this only creates a shallow copy of the component.

Return type:

None

Returns:

A copy of the component.

Examples

Create a shallow copy of a component:

>>> from icalendar import Event
>>> event = Event.new(description="Event to be copied")
>>> event_copy = event.copy()
>>> str(event_copy.description)
'Event to be copied'

Shallow copies lose their subcomponents:

>>> from icalendar import Calendar
>>> calendar = Calendar.example()
>>> len(calendar.subcomponents)
3
>>> calendar_copy = calendar.copy()
>>> len(calendar_copy.subcomponents)
0

A recursive copy also copies all the subcomponents:

>>> full_calendar_copy = calendar.copy(recursive=True)
>>> len(full_calendar_copy.subcomponents)
3
>>> full_calendar_copy.events[0] == calendar.events[0]
True
>>> full_calendar_copy.events[0] is calendar.events[0]
False
property created: datetime#

Datetime when the information associated with the component was created.

Since CREATED is an optional property, this returns DTSTAMP if CREATED is not set.

decoded(name, default=[])#

Returns decoded value of property.

A component maps keys to icalendar property value types. This function returns values compatible to native Python types.

Return type:

Any

property description: str | None#

DESCRIPTION provides a more complete description of the calendar component than that provided by the "SUMMARY" property.

Property Parameters:

IANA, non-standard, alternate text representation, and language property parameters can be specified on this property.

Conformance:

The property can be specified in the "VEVENT", "VTODO", "VJOURNAL", or "VALARM" calendar components. The property can be specified multiple times only within a "VJOURNAL" calendar component.

Description:

This property is used in the "VEVENT" and "VTODO" to capture lengthy textual descriptions associated with the activity.

This property is used in the "VALARM" calendar component to capture the display text for a DISPLAY category of alarm, and to capture the body text for an EMAIL category of alarm.

Examples

The following is an example of this property with formatted line breaks in the property value:

DESCRIPTION:Meeting to provide technical review for "Phoenix"
 design.\nHappy Face Conference Room. Phoenix design team
 MUST attend this meeting.\nRSVP to team leader.
property duration: timedelta | None#

Compute the duration of this component.

If there is no DTEND or DURATION set, this is None. Otherwise, the duration is calculated from DTSTART and DTEND/DURATION.

This is in accordance with RFC 7953: If "DTEND" or "DURATION" are not present, then the end time is unbounded.

property end: timedelta | None#

Compute the duration of this component.

If there is no DTEND or DURATION set, this is None. Otherwise, the duration is calculated from DTSTART and DTEND/DURATION.

This is in accordance with RFC 7953: If "DTEND" or "DURATION" are not present, then the end time is unbounded.

classmethod example(name='rfc_7953_1')[source]#

Return the calendar example with the given name.

Return type:

Availability

exclusive: ClassVar[tuple[()]] = ('DTEND', 'DURATION')#

These properties are mutually exclusive.

classmethod from_ical(st, multiple=False)#

Parse iCalendar data into component instances.

Handles standard and custom components (X-*, IANA-registered).

Parameters:
  • st (str | bytes) – iCalendar data as bytes or string

  • multiple (bool) – If True, returns list. If False, returns single component.

Return type:

Component | list[Component]

Returns:

Component or list of components

See also

Custom components for examples of parsing custom components

classmethod from_jcal(jcal)#

Create a component from a jCal list.

Parameters:

jcal (str | list) – jCal list or JSON string according to RFC 7265.

Raises:
Return type:

Component

This reverses to_json() and to_jcal().

The following code parses an example from RFC 7265:

>>> from icalendar import Component
>>> jcal = ["vcalendar",
...   [
...     ["calscale", {}, "text", "GREGORIAN"],
...     ["prodid", {}, "text", "-//Example Inc.//Example Calendar//EN"],
...     ["version", {}, "text", "2.0"]
...   ],
...   [
...     ["vevent",
...       [
...         ["dtstamp", {}, "date-time", "2008-02-05T19:12:24Z"],
...         ["dtstart", {}, "date", "2008-10-06"],
...         ["summary", {}, "text", "Planning meeting"],
...         ["uid", {}, "text", "4088E990AD89CB3DBB484909"]
...       ],
...       []
...     ]
...   ]
... ]
>>> calendar = Component.from_jcal(jcal)
>>> print(calendar.name)
VCALENDAR
>>> print(calendar.prodid)
-//Example Inc.//Example Calendar//EN
>>> event = calendar.events[0]
>>> print(event.summary)
Planning meeting
classmethod fromkeys(iterable, value=None)#

Create a new ordered dictionary with keys from iterable and values set to value.

get(key, default=None)#

Get property value with default.

classmethod get_component_class(name)#

Return a component with this name.

Parameters:

name (str) – Name of the component, i.e. VCALENDAR

Return type:

type[Component]

get_inline(name, decode=1)#

Returns a list of values (split on comma).

ignore_exceptions: ClassVar[bool] = False#

Whether or not to ignore exceptions when parsing.

If True, and this component can't be parsed, then it will silently ignore it, rather than let the exception propagate upwards.

inclusive: ClassVar[tuple[str] | tuple[tuple[str, str]]] = ()#

These properties are inclusive.

In other words, if the first property in the tuple occurs, then the second one must also occur.

Example

('duration', 'repeat')
is_empty()#

Returns True if Component has no items or subcomponents, else False.

is_thunderbird()#

Whether this component has attributes that indicate that Mozilla Thunderbird created it.

Return type:

bool

items()#

Return a set-like object providing a view on the dict's items.

keys()#

Return a set-like object providing a view on the dict's keys.

property last_modified: datetime#

Datetime when the information associated with the component was last revised.

Since LAST_MODIFIED is an optional property, this returns DTSTAMP if LAST_MODIFIED is not set.

LINK properties as a list.

Purpose:

LINK provides a reference to external information related to a component.

Property Parameters:

The VALUE parameter is required. Non-standard, link relation type, format type, label, and language parameters can also be specified on this property. The LABEL parameter is defined in RFC 7986.

Conformance:

This property can be specified zero or more times in any iCalendar component. LINK is specified in RFC 9253. The LINKREL parameter is required.

Description:

When used in a component, the value of this property points to additional information related to the component. For example, it may reference the originating web server.

This property is a serialization of the model in RFC 8288, where the link target is carried in the property value, the link context is the containing calendar entity, and the link relation type and any target attributes are carried in iCalendar property parameters.

The LINK property parameters map to RFC 8288 attributes as follows:

LABEL

This parameter maps to the "title" attribute defined in Section 3.4.1 of RFC 8288. LABEL is used to label the destination of a link such that it can be used as a human-readable identifier (e.g., a menu entry) in the language indicated by the LANGUAGE (if present).

LANGUAGE

This parameter maps to the "hreflang" attribute defined in Section 3.4.1 of RFC 8288. See RFC 5646. Example: en, de-ch.

LINKREL

This parameter maps to the link relation type defined in Section 2.1 of RFC 8288. See Registered Link Relation Types.

FMTTYPE

This parameter maps to the "type" attribute defined in Section 3.4.1 of RFC 8288.

There is no mapping for "title*", "anchor", "rev", or "media" RFC 8288.

Examples

The following is an example of this property, which provides a reference to the source for the calendar object.

LINK;LINKREL=SOURCE;LABEL=Venue;VALUE=URI:
 https://example.com/events

The following is an example of this property, which provides a reference to an entity from which this one was derived. The link relation is a vendor-defined value.

LINK;LINKREL="https://example.com/linkrel/derivedFrom";
 VALUE=URI:
 https://example.com/tasks/01234567-abcd1234.ics

The following is an example of this property, which provides a reference to a fragment of an XML document. The link relation is a vendor-defined value.

LINK;LINKREL="https://example.com/linkrel/costStructure";
 VALUE=XML-REFERENCE:
 https://example.com/xmlDocs/bidFramework.xml
 #xpointer(descendant::CostStruc/range-to(
 following::CostStrucEND[1]))

Set a link icalendar.vUri to the event page:

>>> from icalendar import Event, vUri
>>> from datetime import datetime
>>> link = vUri(
...     "http://example.com/event-page",
...     params={"LINKREL":"SOURCE"}
... )
>>> event = Event.new(
...     start=datetime(2025, 9, 17, 12, 0),
...     summary="An Example Event with a page"
... )
>>> event.links = [link]
>>> print(event.to_ical())
BEGIN:VEVENT
SUMMARY:An Example Event with a page
DTSTART:20250917T120000
DTSTAMP:20250517T080612Z
UID:d755cef5-2311-46ed-a0e1-6733c9e15c63
LINK;LINKREL="SOURCE":http://example.com/event-page
END:VEVENT
property location: str | None#

The intended venue for the activity defined by a calendar component.

Property Parameters:

IANA, non-standard, alternate text representation, and language property parameters can be specified on this property.

Conformance:

Since RFC 5545, this property can be specified in "VEVENT" or "VTODO" calendar component. RFC 7953 adds this property to "VAVAILABILITY" and "VAVAILABLE".

Description:

Specific venues such as conference or meeting rooms may be explicitly specified using this property. An alternate representation may be specified that is a URI that points to directory information with more structured specification of the location. For example, the alternate representation may specify either an LDAP URL RFC 4516 pointing to an LDAP server entry or a CID URL RFC 2392 pointing to a MIME body part containing a Virtual-Information Card (vCard) RFC 2426 for the location.

move_to_end(key, last=True)#

Move an existing element to the end (or beginning if last is false).

Raise KeyError if the element does not exist.

multiple: ClassVar[tuple[()]] = ()#

These properties may occur more than once.

name: ClassVar[str | None] = 'VAVAILABILITY'#

The name of the component.

This should be defined in each component class.

Example: VCALENDAR.

classmethod new(busy_type=None, categories=(), comments=None, components=(), concepts=None, contacts=None, created=None, classification=None, description=None, end=None, last_modified=None, links=None, location=None, organizer=None, priority=None, refids=None, related_to=None, sequence=None, stamp=None, start=None, summary=None, uid=None, url=None)[source]#

Create a new event with all required properties.

This creates a new Availability in accordance with RFC 7953.

Parameters:
Returns:

Availability

Raises:

InvalidCalendar – If the content is not valid according to RFC 7953.

Warning

As time progresses, we will be stricter with the validation.

property organizer: vCalAddress | None#

ORGANIZER defines the organizer for a calendar component.

Property Parameters:

IANA, non-standard, language, common name, directory entry reference, and sent-by property parameters can be specified on this property.

Conformance:

This property MUST be specified in an iCalendar object that specifies a group-scheduled calendar entity. This property MUST be specified in an iCalendar object that specifies the publication of a calendar user's busy time. This property MUST NOT be specified in an iCalendar object that specifies only a time zone definition or that defines calendar components that are not group-scheduled components, but are components only on a single user's calendar.

Description:

This property is specified within the "VEVENT", "VTODO", and "VJOURNAL" calendar components to specify the organizer of a group-scheduled calendar entity. The property is specified within the "VFREEBUSY" calendar component to specify the calendar user requesting the free or busy time. When publishing a "VFREEBUSY" calendar component, the property is used to specify the calendar that the published busy time came from.

The property has the property parameters "CN", for specifying the common or display name associated with the "Organizer", "DIR", for specifying a pointer to the directory information associated with the "Organizer", "SENT-BY", for specifying another calendar user that is acting on behalf of the "Organizer". The non-standard parameters may also be specified on this property. If the "LANGUAGE" property parameter is specified, the identified language applies to the "CN" parameter value.

property priority: int#
Conformance:

This property can be specified in "VEVENT" and "VTODO" calendar components according to RFC 5545. RFC 7953 adds this property to "VAVAILABILITY".

Description:

This priority is specified as an integer in the range 0 to 9. A value of 0 specifies an undefined priority. A value of 1 is the highest priority. A value of 2 is the second highest priority. Subsequent numbers specify a decreasing ordinal priority. A value of 9 is the lowest priority.

A CUA with a three-level priority scheme of "HIGH", "MEDIUM", and "LOW" is mapped into this property such that a property value in the range of 1 to 4 specifies "HIGH" priority. A value of 5 is the normal or "MEDIUM" priority. A value in the range of 6 to 9 is "LOW" priority.

A CUA with a priority schema of "A1", "A2", "A3", "B1", "B2", …, "C3" is mapped into this property such that a property value of 1 specifies "A1", a property value of 2 specifies "A2", a property value of 3 specifies "A3", and so forth up to a property value of 9 specifies "C3".

Other integer values are reserved for future use.

Within a "VEVENT" calendar component, this property specifies a priority for the event. This property may be useful when more than one event is scheduled for a given time period.

Within a "VTODO" calendar component, this property specified a priority for the to-do. This property is useful in prioritizing multiple action items for a given time period.

property_items(recursive=True, sorted=True)#

Returns properties in this component and subcomponents as: [(name, value), …]

Return type:

list[tuple[str, object]]

property refids: list[str]#

REFID

Purpose:

REFID acts as a key for associated iCalendar entities.

Conformance:

Since RFC 9253, this property can be specified zero or more times in any iCalendar component.

Description:

The value of this property is free-form text that creates an identifier for associated components. All components that use the same REFID value are associated through that value and can be located or retrieved as a group. For example, all of the events in a travel itinerary would have the same REFID value, so as to be grouped together.

Examples

The following is an example of this property.

REFID:itinerary-2014-11-17

Use a REFID to associate several VTODOs:

>>> from icalendar import Todo
>>> todo_1 = Todo.new(
...     summary="turn off stove",
...     refids=["travel", "alps"]
... )
>>> todo_2 = Todo.new(
...     summary="pack backpack",
...     refids=["travel", "alps"]
... )
>>> todo_1.refids == todo_2.refids
True

Note

List modifications do not modify the component.

classmethod register(component_class)#

Register a custom component class.

Parameters:

component_class (type[Component]) – Component subclass to register. Must have a name attribute.

Raises:
  • ValueError – If component_class has no name attribute.

  • ValueError – If a component with this name is already registered.

Return type:

None

Examples

Create a custom icalendar component with the name X-EXAMPLE:

>>> from icalendar import Component
>>> class XExample(Component):
...     name = "X-EXAMPLE"
...     def custom_method(self):
...         return "custom"
>>> Component.register(XExample)
property related_to: list[vText | vUri | vUid]#

RELATED-TO properties as a list.

Purpose:

This property is used to represent a relationship or reference between one calendar component and another. RFC 9523 allows URI or UID values and a GAP parameter.

Value Type:

RFC 5545: TEXT RFC 9253: URI, UID

Conformance:

Since RFC 5545. this property can be specified in the "VEVENT", "VTODO", and "VJOURNAL" calendar components. Since RFC 9523, this property MAY be specified in any iCalendar component.

Description (RFC 5545):

The property value consists of the persistent, globally unique identifier of another calendar component. This value would be represented in a calendar component by the "UID" property.

By default, the property value points to another calendar component that has a PARENT relationship to the referencing object. The "RELTYPE" property parameter is used to either explicitly state the default PARENT relationship type to the referenced calendar component or to override the default PARENT relationship type and specify either a CHILD or SIBLING relationship. The PARENT relationship indicates that the calendar component is a subordinate of the referenced calendar component. The CHILD relationship indicates that the calendar component is a superior of the referenced calendar component. The SIBLING relationship indicates that the calendar component is a peer of the referenced calendar component.

Changes to a calendar component referenced by this property can have an implicit impact on the related calendar component. For example, if a group event changes its start or end date or time, then the related, dependent events will need to have their start and end dates changed in a corresponding way. Similarly, if a PARENT calendar component is cancelled or deleted, then there is an implied impact to the related CHILD calendar components. This property is intended only to provide information on the relationship of calendar components. It is up to the target calendar system to maintain any property implications of this relationship.

Description (RFC 9253):

By default or when VALUE=UID is specified, the property value consists of the persistent, globally unique identifier of another calendar component. This value would be represented in a calendar component by the UID property.

By default, the property value points to another calendar component that has a PARENT relationship to the referencing object. The RELTYPE property parameter is used to either explicitly state the default PARENT relationship type to the referenced calendar component or to override the default PARENT relationship type and specify either a CHILD or SIBLING relationship or a temporal relationship.

The PARENT relationship indicates that the calendar component is a subordinate of the referenced calendar component. The CHILD relationship indicates that the calendar component is a superior of the referenced calendar component. The SIBLING relationship indicates that the calendar component is a peer of the referenced calendar component.

To preserve backwards compatibility, the value type MUST be UID when the PARENT, SIBLING, or CHILD relationships are specified.

The FINISHTOSTART, FINISHTOFINISH, STARTTOFINISH, or STARTTOSTART relationships define temporal relationships, as specified in the RELTYPE parameter definition.

The FIRST and NEXT define ordering relationships between calendar components.

The DEPENDS-ON relationship indicates that the current calendar component depends on the referenced calendar component in some manner. For example, a task may be blocked waiting on the other, referenced, task.

The REFID and CONCEPT relationships establish a reference from the current component to the referenced component. Changes to a calendar component referenced by this property can have an implicit impact on the related calendar component. For example, if a group event changes its start or end date or time, then the related, dependent events will need to have their start and end dates and times changed in a corresponding way. Similarly, if a PARENT calendar component is canceled or deleted, then there is an implied impact to the related CHILD calendar components. This property is intended only to provide information on the relationship of calendar components.

Deletion of the target component, for example, the target of a FIRST, NEXT, or temporal relationship, can result in broken links.

It is up to the target calendar system to maintain any property implications of these relationships.

Examples

RFC 5545 examples of this property:

RELATED-TO:jsmith.part7.19960817T083000.xyzMail@example.com
RELATED-TO:19960401-080045-4000F192713-0052@example.com

RFC 9253 examples of this property:

RELATED-TO;VALUE=URI;RELTYPE=STARTTOFINISH:
 https://example.com/caldav/user/jb/cal/
 19960401-080045-4000F192713.ics

See also icalendar.enum.RELTYPE.

required: ClassVar[tuple[()]] = ('DTSTART', 'DTSTAMP', 'UID')#

These properties are required.

property sequence: int#

This property defines the revision sequence number of the calendar component within a sequence of revisions.

Value Type:

INTEGER

Property Parameters:

IANA and non-standard property parameters can be specified on this property.

Conformance:

The property can be specified in "VEVENT", "VTODO", or "VJOURNAL" calendar component.

Description:

When a calendar component is created, its sequence number is 0. It is monotonically incremented by the "Organizer's" CUA each time the "Organizer" makes a significant revision to the calendar component.

The "Organizer" includes this property in an iCalendar object that it sends to an "Attendee" to specify the current version of the calendar component.

The "Attendee" includes this property in an iCalendar object that it sends to the "Organizer" to specify the version of the calendar component to which the "Attendee" is referring.

A change to the sequence number is not the mechanism that an "Organizer" uses to request a response from the "Attendees". The "RSVP" parameter on the "ATTENDEE" property is used by the "Organizer" to indicate that a response from the "Attendees" is requested.

Recurrence instances of a recurring component MAY have different sequence numbers.

Examples

The following is an example of this property for a calendar component that was just created by the "Organizer":

>>> from icalendar import Event
>>> event = Event()
>>> event.sequence
0

The following is an example of this property for a calendar component that has been revised 10 different times by the "Organizer":

>>> from icalendar import Calendar
>>> calendar = Calendar.example("issue_156_RDATE_with_PERIOD_TZID_khal")
>>> event = calendar.events[0]
>>> event.sequence
10
set_inline(name, values, encode=1)#

Converts a list of values into comma separated string and sets value to that.

singletons: ClassVar[tuple[()]] = ('DTSTAMP', 'UID', 'BUSYTYPE', 'CLASS', 'CREATED', 'DESCRIPTION', 'DTSTART', 'LAST-MODIFIED', 'LOCATION', 'ORGANIZER', 'PRIORITY', 'SEQUENCE', 'SUMMARY', 'URL', 'DTEND', 'DURATION')#

These properties must appear only once.

property stamp: datetime | None#

The DTSTAMP property. datetime in UTC

All values will be converted to a datetime in UTC. RFC 5545:

Conformance: This property MUST be included in the "VEVENT", "VTODO", "VJOURNAL", or "VFREEBUSY" calendar components.

Description: In the case of an iCalendar object that specifies a "METHOD" property, this property specifies the date and time that the instance of the iCalendar object was created. In the case of an iCalendar object that doesn't specify a "METHOD" property, this property specifies the date and time that the information associated with the calendar component was last revised in the calendar store.

The value MUST be specified in the UTC time format.

In the case of an iCalendar object that doesn't specify a "METHOD" property, this property is equivalent to the "LAST-MODIFIED" property.

property start: datetime | None#

The DTSTART property. datetime in UTC

All values will be converted to a datetime in UTC. Start of the component.

This is almost the same as Event.DTSTART with one exception: The values MUST have a timezone and DATE is not allowed.

Description:

RFC 7953: If specified, the "DTSTART" and "DTEND" properties in "VAVAILABILITY" components and "AVAILABLE" subcomponents MUST be "DATE-TIME" values specified as either the date with UTC time or the date with local time and a time zone reference.

subcomponents: list[Component]#

All subcomponents of this component.

property summary: str | None#

SUMMARY defines a short summary or subject for the calendar component.

Property Parameters:

IANA, non-standard, alternate text representation, and language property parameters can be specified on this property.

Conformance:

The property can be specified in "VEVENT", "VTODO", "VJOURNAL", or "VALARM" calendar components.

Description:

This property is used in the "VEVENT", "VTODO", and "VJOURNAL" calendar components to capture a short, one-line summary about the activity or journal entry.

This property is used in the "VALARM" calendar component to capture the subject of an EMAIL category of alarm.

Examples

The following is an example of this property:

SUMMARY:Department Party
to_ical(sorted=True)#
Parameters:

sorted (bool) – Whether parameters and properties should be lexicographically sorted.

to_jcal()#

Convert this component to a jCal object.

Return type:

list

Returns:

jCal object

See also to_json.

In this example, we create a simple VEVENT component and convert it to jCal:

>>> from icalendar import Event
>>> from datetime import date
>>> from pprint import pprint
>>> event = Event.new(summary="My Event", start=date(2025, 11, 22))
>>> pprint(event.to_jcal())
['vevent',
 [['dtstamp', {}, 'date-time', '2025-05-17T08:06:12Z'],
  ['summary', {}, 'text', 'My Event'],
  ['uid', {}, 'text', 'd755cef5-2311-46ed-a0e1-6733c9e15c63'],
  ['dtstart', {}, 'date', '2025-11-22']],
 []]
to_json()#

Return this component as a jCal JSON string.

Return type:

str

Returns:

JSON string

See also to_jcal.

types_factory: ClassVar[TypesFactory] = {'ADR': <class 'icalendar.prop.adr.vAdr'>, 'BINARY': <class 'icalendar.prop.binary.vBinary'>, 'BOOLEAN': <class 'icalendar.prop.boolean.vBoolean'>, 'CAL-ADDRESS': <class 'icalendar.prop.cal_address.vCalAddress'>, 'CATEGORIES': <class 'icalendar.prop.categories.vCategory'>, 'DATE': <class 'icalendar.prop.dt.types.vDDDTypes'>, 'DATE-TIME': <class 'icalendar.prop.dt.types.vDDDTypes'>, 'DATE-TIME-LIST': <class 'icalendar.prop.dt.list.vDDDLists'>, 'DURATION': <class 'icalendar.prop.dt.types.vDDDTypes'>, 'FLOAT': <class 'icalendar.prop.float.vFloat'>, 'GEO': <class 'icalendar.prop.geo.vGeo'>, 'INLINE': <class 'icalendar.prop.inline.vInline'>, 'INTEGER': <class 'icalendar.prop.integer.vInt'>, 'N': <class 'icalendar.prop.n.vN'>, 'ORG': <class 'icalendar.prop.org.vOrg'>, 'PERIOD': <class 'icalendar.prop.dt.period.vPeriod'>, 'RECUR': <class 'icalendar.prop.recur.recur.vRecur'>, 'TEXT': <class 'icalendar.prop.text.vText'>, 'TIME': <class 'icalendar.prop.dt.time.vTime'>, 'UID': <class 'icalendar.prop.uid.vUid'>, 'UNKNOWN': <class 'icalendar.prop.unknown.vUnknown'>, 'URI': <class 'icalendar.prop.uri.vUri'>, 'UTC-OFFSET': <class 'icalendar.prop.dt.utc_offset.vUTCOffset'>, 'XML-REFERENCE': <class 'icalendar.prop.xml_reference.vXmlReference'>}#
property uid: str#

UID specifies the persistent, globally unique identifier for a component.

We recommend using uuid.uuid4() to generate new values.

Returns:

The value of the UID property as a string or "" if no value is set.

Description:

The "UID" itself MUST be a globally unique identifier. The generator of the identifier MUST guarantee that the identifier is unique.

This is the method for correlating scheduling messages with the referenced "VEVENT", "VTODO", or "VJOURNAL" calendar component. The full range of calendar components specified by a recurrence set is referenced by referring to just the "UID" property value corresponding to the calendar component. The "RECURRENCE-ID" property allows the reference to an individual instance within the recurrence set.

This property is an important method for group-scheduling applications to match requests with later replies, modifications, or deletion requests. Calendaring and scheduling applications MUST generate this property in "VEVENT", "VTODO", and "VJOURNAL" calendar components to assure interoperability with other group- scheduling applications. This identifier is created by the calendar system that generates an iCalendar object.

Implementations MUST be able to receive and persist values of at least 255 octets for this property, but they MUST NOT truncate values in the middle of a UTF-8 multi-octet sequence.

RFC 7986 states that UID can be used, for example, to identify duplicate calendar streams that a client may have been given access to. It can be used in conjunction with the "LAST-MODIFIED" property also specified on the "VCALENDAR" object to identify the most recent version of a calendar.

Conformance:

RFC 5545 states that the "UID" property can be specified on "VEVENT", "VTODO", and "VJOURNAL" calendar components. RFC 7986 modifies the definition of the "UID" property to allow it to be defined in an iCalendar object. RFC 9074 adds a "UID" property to "VALARM" components to allow a unique identifier to be specified. The value of this property can then be used to refer uniquely to the "VALARM" component.

This property can be specified once only.

Security:

RFC 7986 states that UID values MUST NOT include any data that might identify a user, host, domain, or any other security- or privacy-sensitive information. It is RECOMMENDED that calendar user agents now generate "UID" values that are hex-encoded random Universally Unique Identifier (UUID) values as defined in Sections 4.4 and 4.5 of RFC 4122. You can use the uuid module to generate new UUIDs.

Compatibility:

For Alarms, X-ALARMUID is also considered.

Examples

The following is an example of such a property value: 5FC53010-1267-4F8E-BC28-1D7AE55A7C99.

Set the UID of a calendar:

>>> from icalendar import Calendar
>>> from uuid import uuid4
>>> calendar = Calendar()
>>> calendar.uid = uuid4()
>>> print(calendar.to_ical())
BEGIN:VCALENDAR
UID:d755cef5-2311-46ed-a0e1-6733c9e15c63
END:VCALENDAR
property url: str#

A Uniform Resource Locator (URL) associated with the iCalendar object.

Description:

This property may be used in a calendar component to convey a location where a more dynamic rendition of the calendar information associated with the calendar component can be found. This memo does not attempt to standardize the form of the URI, nor the format of the resource pointed to by the property value. If the URL property and Content-Location MIME header are both specified, they MUST point to the same resource.

Conformance:

This property can be specified once in the "VEVENT", "VTODO", "VJOURNAL", or "VFREEBUSY" calendar components. Since RFC 7986, this property can also be defined on a "VCALENDAR".

Example

The following is an example of this property:

URL:http://example.com/pub/calendars/jsmith/mytime.ics
values()#

Return an object providing a view on the dict's values.

walk(name=None, select=<function Component.<lambda>>)#

Recursively traverses component and subcomponents. Returns sequence of same. If name is passed, only components with name will be returned.

Parameters:
  • name – The name of the component or None such as VEVENT.

  • select – A function that takes the component as first argument and returns True/False.

Returns:

A list of components that match.

Return type:

list[Component]

with_uid(uid)#

Return a list of components with the given UID.

Parameters:

uid (str) – The UID of the component.

Returns:

List of components with the given UID.

Return type:

list[Component]