==========
Change log
==========

.. py:currentmodule:: icalendar

.. Do *NOT* add new change log entries to this file.
   Instead create a file in the news directory.
   For helpful instructions, see:
   https://icalendar.readthedocs.io/en/latest/contribute/#change-log-entry-format

.. towncrier release notes start

7.2.2 (2026-07-20)
------------------

Documentation
~~~~~~~~~~~~~

- Fixed duplicate ``vInt.min`` and ``vInt.max`` descriptions in the API reference that caused the Read the Docs build to fail.


7.2.1 (2026-07-20)
------------------

Security fixes
~~~~~~~~~~~~~~

- Fixed `GHSA-qjcq-q7h7-r74v <https://github.com/collective/icalendar/security/advisories/GHSA-qjcq-q7h7-r74v>`_: a crafted ``REPEAT`` on a ``VALARM`` could exhaust memory or CPU via :attr:`Alarm.triggers <icalendar.cal.alarm.Alarm.triggers>` and :class:`~icalendar.alarms.Alarms`. Expansion is now capped at ``icalendar.config.MAX_ALARM_REPEAT``. Its default is ``10000``. Set to ``-1`` to disable the cap. :class:`~icalendar.prop.integer.vInt` now also enforces the :rfc:`5545` signed 32-bit integer range on parse. @SashankBhamidi


7.2.0 (2026-06-23)
------------------

Removals and deprecations
~~~~~~~~~~~~~~~~~~~~~~~~~

- Deprecated :func:`icalendar.parser.string.foldline` as a private function for icalendar version 8. @IoannaGiag (`Issue #1011 <https://github.com/collective/icalendar/issues/1011>`_)
- Deprecated :func:`icalendar.parser.string.escape_char`, :func:`icalendar.parser.string.unescape_char`, :func:`icalendar.parser.string.escape_string`, and :func:`icalendar.parser.string.unescape_string` using the standard ``deprecate_for_version_8`` wrapper as per issue #1405. (`Issue #1405 <https://github.com/collective/icalendar/issues/1405>`_)


New features
~~~~~~~~~~~~

- Created an :attr:`~icalendar.prop.recur.frequency.vFrequency.ical_value` property for the :class:`~icalendar.prop.recur.frequency.vFrequency` component, mirroring the existing pattern on :class:`~icalendar.prop.recur.weekday.vWeekday`. @mvanhorn (`Issue #876 <https://github.com/collective/icalendar/issues/876>`_)
- Created an :attr:`~icalendar.prop.geo.vGeo.ical_value` property for the :class:`~icalendar.prop.geo.vGeo` component. @IoannaGiag (`Issue #876 <https://github.com/collective/icalendar/issues/876>`_)
- Added type hints to component methods. @Priyanshu-pulak (`Issue #938 <https://github.com/collective/icalendar/issues/938>`_)
- Added test coverage for :func:`icalendar.compatibility.deprecate_for_version_8`. AI disclosure: I used GPT-5 Codex to help draft and refine the test and pull request text. I reviewed the output and validated the change locally. @iccccccccccccc (`Issue #1407 <https://github.com/collective/icalendar/issues/1407>`_)
- The :attr:`Alarm.uid <icalendar.cal.alarm.Alarm.uid>` accessor now falls back to vendor-specific UID properties (the existing ``X-ALARMUID`` and the newly added ``X-EVOLUTION-ALARM-UID``) when no canonical ``UID`` is present, so alarms exported by Evolution/GNOME Calendar expose a usable identifier. ``single_string_property`` now accepts an ordered list of fallback keys so further vendor aliases can be added later. AI disclosure: I used GPT-5 Codex (via the Codex CLI) to draft and refine this change and its tests; I reviewed and validated the output locally. @mvanhorn (`Issue #1421 <https://github.com/collective/icalendar/issues/1421>`_)
- The ``rdates`` and ``exdates`` properties are now writable: assigning a list replaces the ``RDATE``/``EXDATE`` values, ``del`` (or assigning an empty list or ``None``) clears them, and assigning the value the getter returns round-trips. Prepared with the assistance of an AI coding agent (Anthropic's Claude). @gaoflow (`Issue #1442 <https://github.com/collective/icalendar/issues/1442>`_)


Bug fixes
~~~~~~~~~

- Strictly validate :class:`~icalendar.prop.dt.datetime.vDatetime` values in :meth:`~icalendar.prop.dt.datetime.vDatetime.from_ical` and reject malformed input. This also improves handling of values with a ``TZID`` prefix, per :rfc:`5545#section-3.3.5`, Form #3. @uwezkhan (`Issue #1361 <https://github.com/collective/icalendar/issues/1361>`_)
- Preserve an explicit ``VALUE`` parameter (for example ``RDATE;VALUE=PERIOD`` or ``TRIGGER;VALUE=DATE-TIME``) when converting from jCal. Previously :meth:`Component.from_jcal <icalendar.cal.component.Component.from_jcal>` dropped the value type, which is encoded in the jCal type field rather than as a parameter. Prepared with the assistance of an AI coding agent (Anthropic's Claude Opus 4). @gaoflow @lcampanella98 (`Issue #1426 <https://github.com/collective/icalendar/issues/1426>`_)
- For a newline-free string that the operating system can't use as a file path—for example, one containing an embedded null byte or one that is too long—treat it as calendar data, instead of propagating an :exc:`OSError` from :meth:`Component.from_ical <icalendar.cal.component.Component.from_ical>`. Such input now raises a consistent :exc:`ValueError` across platforms. The string-versus-path boundary is now covered by tests. @uwezkhan (`Issue #1436 <https://github.com/collective/icalendar/issues/1436>`_)
- Accept the ``(dt, None)`` form that ``rdates``/``exdates`` return for a single date when adding ``RDATE`` or ``EXDATE``, so ``event.add("RDATE", (dt, None))`` no longer raises :exc:`TypeError` and the value round-trips. Prepared with the assistance of an AI coding agent (Anthropic's Claude Opus 4). @gaoflow @texttheater (`Issue #1439 <https://github.com/collective/icalendar/issues/1439>`_)
- Anchored the value validation regular expressions with ``\Z`` instead of ``$`` in :class:`~icalendar.prop.recur.weekday.vWeekday`, :meth:`vDuration.from_ical <icalendar.prop.dt.duration.vDuration.from_ical>`, :class:`~icalendar.prop.dt.time.vTime` and :class:`~icalendar.prop.dt.utc_offset.vUTCOffset`. ``$`` matches just before a final ``\n``, so a value with a trailing line break was accepted; for ``vWeekday`` the newline survived in the ``str`` value and was re-emitted into RECUR output. @alhudz
- For iCalendar files that have thousands of bare line breaks, reduce the content line parse time by a quadratic order of magnitude when reading a component with :meth:`Component.from_ical <icalendar.cal.component.Component.from_ical>`. @alhudz
- Parse a ``CATEGORIES`` value that contains an unescaped colon correctly. ``TEXT`` values do not escape ``:``, so a category such as ``CATEGORIES:CONFIDENTIAL,http://example.com/tag`` was truncated to a single ``//example.com/tag`` because the value boundary was found with the last colon on the line instead of the first one outside the parameters. @alhudz
- Parse and serialize jCal iteratively so that deeply nested components no longer raise an uncaught :exc:`RecursionError`. :meth:`Component.from_jcal <icalendar.cal.component.Component.from_jcal>` and :meth:`Component.to_jcal <icalendar.cal.component.Component.to_jcal>` now handle arbitrary nesting depth, matching the iterative iCal parser and serializer. @arshsmith
- Preserve literal percent escapes in parameter values. The parameter parser used ``%2C``/``%3A``/``%3B``/``%5C`` as internal markers for backslash-escaped delimiters, so a value that already contained those sequences (e.g. ``ALTREP="http://x/a%2Cb"``) was silently decoded to ``http://x/a,b``. The internal transport encoding now escapes ``%`` itself, leaving real percent-encoded values untouched. @alhudz
- Raise :class:`~icalendar.error.InvalidCalendar` instead of leaking :exc:`OverflowError` when a ``DURATION`` value is too large for :class:`datetime.timedelta`, for example, ``P999999999999999999W``. Parsing a whole calendar now records such a value as an error, like any other invalid property, rather than aborting the parse. @arshsmith
- Reject non-ASCII digits in :class:`~icalendar.prop.recur.month.vMonth` (``BYMONTH``). ``str.isdigit`` is ``True`` for digits like the Arabic-Indic ``١٢``, which was silently accepted and normalized to month ``12``, while characters such as ``²`` cleared the same guard and then leaked a raw ``int()`` error. :meth:`vMonth.from_ical <icalendar.prop.recur.month.vMonth.from_ical>` now rejects both. @alhudz
- Reject non-finite FLOAT values in :meth:`vFloat.from_ical() <icalendar.prop.float.vFloat.from_ical>` and :meth:`vGeo.from_ical() <icalendar.prop.geo.vGeo.from_ical>`. Inputs such as ``nan``, ``inf`` or an overflowing magnitude like ``1e999`` were silently accepted, producing ``NaN``/``Infinity`` tokens in :meth:`Component.to_json <icalendar.cal.component.Component.to_json>` output that are not valid JSON. @alhudz
- Strictly validate :class:`~icalendar.prop.dt.date.vDate` and :class:`~icalendar.prop.dt.time.vTime` values in their ``from_ical`` methods and reject malformed input, matching the strictness added to :class:`~icalendar.prop.dt.datetime.vDatetime`. Trailing data and ``int()`` quirks (underscores, whitespace, signs) are no longer silently accepted, per :rfc:`5545#section-3.3.4` and :rfc:`5545#section-3.3.12`. This change was prepared with AI assistance (Anthropic Claude, Opus model, via Claude Code) used to research the relevant RFC grammar and draft the validation and tests, all reviewed and verified locally. @alhudz


Documentation
~~~~~~~~~~~~~

- Switch :file:`docs/how-to/usage.rst` from the deprecated ``.. code:: pycon`` directive to ``.. code-block:: pycon`` for consistency with the rest of the documentation. @mvanhorn (`Issue #626 <https://github.com/collective/icalendar/issues/626>`_)
- Added type hint for ``encoding`` parameter in :func:`~icalendar.parser_tools.data_encode`. @cybs-joe (`Issue #938 <https://github.com/collective/icalendar/issues/938>`_)
- Converted docstring of :meth:`~icalendar.cal.component.Component.add` to Google style. @mvanhorn (`Issue #1072 <https://github.com/collective/icalendar/issues/1072>`_)
- Fixed broken links and removed `:py` prefix in :class:`icalendar.cal.calendar.Calendar` documentation. @lcampanella98 (`Issue #1158 <https://github.com/collective/icalendar/issues/1158>`_)
- Fixed broken link and removed `:py` prefix in the :func:`~icalendar.parser.unescape_backslash` docstring. @vincere-mori (`Issue #1158 <https://github.com/collective/icalendar/issues/1158>`_)
- Fixed broken documentation links in :mod:`icalendar.alarms` and :mod:`icalendar.cal.alarm`. @lcampanella98 (`Issue #1158 <https://github.com/collective/icalendar/issues/1158>`_)
- Fix unqualified cross-references in :attr:`Event.start <icalendar.cal.event.Event.start>` and :attr:`Event.start <icalendar.cal.event.Event.end>` docstrings. @Esneider1107 (`Issue #1158 <https://github.com/collective/icalendar/issues/1158>`_)
- Fixed broken links in :mod:`icalendar.cal.free_busy` documentation by using fully qualified :class:`icalendar.cal.component.Component` attribute targets. @tsai135 (`Issue #1158 <https://github.com/collective/icalendar/issues/1158>`_)
- Qualify ambiguous cross-references and remove remaining ``:py`` prefixed roles. @wahajahmed010 (`Issue #1158 <https://github.com/collective/icalendar/issues/1158>`_)
- Fixed broken documentation links in :mod:`icalendar.cal.availability`. @lcampanella98 (`Issue #1158 <https://github.com/collective/icalendar/issues/1158>`_)
- Replaced the RFC quotation in the docstring for :class:`vBoolean <icalendar.prop.boolean.vBoolean>` with a Pythonic description, including parsing behavior, a conformance reference, and a working example. @tsai135 (`Issue #1244 <https://github.com/collective/icalendar/issues/1244>`_)
- Improved the documentation for ``attr.url_property`` by converting raw RFC text into a comprehensive Python docstring with usage examples and explicit RFC cross-references. Assisting tool: Gemini 1.5. @samrodri911 (`Issue #1244 <https://github.com/collective/icalendar/issues/1244>`_)
- Improved the :attr:`~icalendar.cal.component.Component.LAST_MODIFIED` docstring to a clearer Pythonic docstring. Assisting tool: Claude Haiku 4.5 @valemm13 (`Issue #1244 <https://github.com/collective/icalendar/issues/1244>`_)
- Tidied the auto-generated property docstrings by removing the redundant accepted values sentence and formatting return and error details as Sphinx sections. @mvanhorn (`Issue #1259 <https://github.com/collective/icalendar/issues/1259>`_)
- Fix Read the Docs administrative instructions in maintenance documentation by removing the obsolete step to check the default branch and adding a step to manually trigger the "latest" version. @stevepiercy (`Issue #1397 <https://github.com/collective/icalendar/issues/1397>`_)
- Clarified that :meth:`Calendar.new <icalendar.cal.calendar.Calendar.new>` automatically sets not only required, but recommended properties too. @scop (`Issue #1459 <https://github.com/collective/icalendar/issues/1459>`_)
- Add how to report security issues. @stevepiercy (`Issue #1463 <https://github.com/collective/icalendar/issues/1463>`_)
- Added NixOS installation instructions to the documentation. @MichaelFehdrau0205
- Added instructions to :ref:`change-log` in Contribute documentation for how to avoid a filename conflict when adding a change log entry. @stevepiercy
- Collect only documentation files for doctest. @stevepiercy
- Documented :meth:`Calendar.from_ical <icalendar.cal.calendar.Calendar.from_ical>` as a direct :class:`~icalendar.cal.calendar.Calendar` API member so Sphinx can link to it from the custom components guide. Prepared with AI assistance. @xjn2005


Internal changes
~~~~~~~~~~~~~~~~

- Added tests for :attr:`FreeBusy.duration <icalendar.cal.free_busy.FreeBusy.duration>` coverage. @kyriakikrimitza (`Issue #698 <https://github.com/collective/icalendar/issues/698>`_)
- Refactored :file:`test_error_tolerant_parsing.py` to use ``.ics`` fixture files. @lcampanella98 (`Issue #1081 <https://github.com/collective/icalendar/issues/1081>`_)
- Added :file:`.pre-commit-config.yaml` configuration and documentation to automatically record AI prompts in commit messages with :program:`ai-prompt-auto-commit`. @AniruthKarthik (`Issue #1320 <https://github.com/collective/icalendar/issues/1320>`_)
- Support keeping a linked issue open in the pull request template when the pull request fixes only a part of the original issue. @stevepiercy (`Issue #1394 <https://github.com/collective/icalendar/issues/1394>`_)
- Trigger the creation of a comment with links to Read the Docs of the changed files to review in a pull request preview build. @stevepiercy (`Issue #1396 <https://github.com/collective/icalendar/issues/1396>`_)
- Add gh-profiler workflow to help triage AI-generated contributions. @SashankBhamidi (`Issue #1484 <https://github.com/collective/icalendar/issues/1484>`_)
- Added validation test for :attr:`FreeBusy.duration <icalendar.cal.free_busy.FreeBusy.duration>`. @kyriakikrimitza
- Remove redundant and deprecated pull request preview feature on Read the Docs. We now use the RTD GitHub app, making this file redundant to pull request preview builds. Additionally the call to the old GitHub Action was deprecated on 2025-07-01, per its `README.md <https://github.com/readthedocs/actions/blob/main/README.md>`_. @stevepiercy


Other tasks
~~~~~~~~~~~

- Added type hints to all methods in the module :mod:`~icalendar.error`. @Priyanshu-pulak (`Issue #938 <https://github.com/collective/icalendar/issues/938>`_)


7.1.3 (2026-06-15)
------------------

Bug fixes
~~~~~~~~~

- Comparing components with ``Component.__eq__`` is no longer exponential in the subcomponent nesting depth, removing a denial-of-service vector where a deeply nested component could take minutes to compare. See `GHSA-cv84-9p8j-fj68 <https://github.com/collective/icalendar/security/advisories/GHSA-cv84-9p8j-fj68>`_. @tidusec


7.1.2 (2026-05-22)
------------------

Bug fixes
~~~~~~~~~

- Replaced the recursive :meth:`Component.__repr__ <icalendar.cal.component.Component.__repr__>` implementation with an iterative stack-based walk so that deeply nested calendars no longer raise :exc:`RecursionError` when formatted via ``repr()``, ``str()``, or f-strings. The output format is unchanged for normally-shaped calendars. @gistrec (`Issue #1370 <https://github.com/collective/icalendar/issues/1370>`_)


Documentation
~~~~~~~~~~~~~

- Update maintenance documentation. Fix the version switcher on "stable" on Read the Docs. @stevepiercy (`Issue #1352 <https://github.com/collective/icalendar/issues/1352>`_)


7.1.1 (2026-05-18)
------------------

New features
~~~~~~~~~~~~

- Created an :attr:`~icalendar.prop.dt.period.vPeriod.ical_value` property for the :class:`~icalendar.prop.dt.period.vPeriod` component. @ZairKSM (`Issue #876 <https://github.com/collective/icalendar/issues/876>`_)
- Created a :meth:`~icalendar.prop.recur.weekday.vWeekday.ical_value` property for the :class:`~icalendar.prop.recur.weekday.vWeekday` component, mirroring the existing pattern on :class:`~icalendar.prop.boolean.vBoolean`. @mvanhorn (`Issue #1360 <https://github.com/collective/icalendar/issues/1360>`_)


Bug fixes
~~~~~~~~~

- Strictly validate BINARY property values in :attr:`vBinary.from_ical() <icalendar.prop.binary.vBinary.from_ical>` and reject malformed Base64 input instead of silently accepting invalid characters. @uwezkhan (`Issue #1349 <https://github.com/collective/icalendar/issues/1349>`_)


Documentation
~~~~~~~~~~~~~

- Replace the RFC quotations in the docstrings for :attr:`Alarm.REPEAT <icalendar.cal.alarm.Alarm.REPEAT>` and :attr:`Alarm.DURATION <icalendar.cal.alarm.Alarm.DURATION>` with Pythonic descriptions, including parameter notes, conformance references, and worked examples. @tmchow (`Issue #1244 <https://github.com/collective/icalendar/issues/1244>`_)
- Edited contributor documentation for how to add a change log entry, and maintenance documentation for how to process news fragments. @stevepiercy (`Issue #1256 <https://github.com/collective/icalendar/issues/1256>`_)
- Updated release process documentation. @niccokunzmann @stevepiercy @SashankBhamidi (`Issue #1293 <https://github.com/collective/icalendar/issues/1293>`_)


Dependency changes
~~~~~~~~~~~~~~~~~~

- Added `towncrier <https://pypi.org/project/towncrier/>`_ to development dependencies. @stevepiercy (`Issue #1256 <https://github.com/collective/icalendar/issues/1256>`_)


Internal changes
~~~~~~~~~~~~~~~~

- Switched from manual change log management to `towncrier <https://pypi.org/project/towncrier/>`_ to automate the process. @stevepiercy (`Issue #1256 <https://github.com/collective/icalendar/issues/1256>`_)
- Bump PyPy from 3.10 to 3.11 for testing. @stevepiercy (`Issue #1383 <https://github.com/collective/icalendar/issues/1383>`_)


7.1.0 (2026-04-30)
------------------

Minor changes
~~~~~~~~~~~~~

- Deprecate ``icalendar.parser.escape_string`` and ``icalendar.parser.unescape_string`` for icalendar version 8. Use ``_escape_string`` and ``_unescape_string`` internally. :issue:`1011`
- Added behavioral tests for :class:`~icalendar.cal.lazy.LazyCalendar` covering serialization round-trips, ``.todos``, ``.journals``, forward timezone references, and ``with_uid()`` substring false-positives. :issue:`1050`
- Added edge case tests for :class:`~icalendar.prop.conference.Conference` parameter normalization covering string passthrough, empty list filtering, and ``None`` omission. :issue:`925`
- Make icalendar an explicit editable install for clarity. :pr:`1268`
- Do not run some tests until a pull request is approved. :pr:`1246`
- Mark skipped CI tasks as skipped instead of running them. :issue:`1286`
- Created an :meth:`~icalendar.prop.boolean.vBoolean.ical_value` property for the :class:`~icalendar.prop.boolean.vBoolean` component. :issue:`876`
- Created an :meth:`~icalendar.prop.float.vFloat.ical_value` property for the :class:`~icalendar.prop.float.vFloat` component. :issue:`876`
- Created an :meth:`~icalendar.prop.integer.vInt.ical_value` property for the :class:`~icalendar.prop.integer.vInt` component. :issue:`876`
- Created an :meth:`~icalendar.prop.binary.vBinary.ical_value` property for the :class:`~icalendar.prop.binary.vBinary` component. :issue:`876`
- Put the link check as the last documentation CI task, allowing the documentation build and Vale to run first and fail faster. :pr:`1295`
- Extended :func:`~icalendar.timezone.tzp.TZP.localize` to support localizing both :class:`datetime.datetime` and :class:`datetime.time` objects, returning timezone-aware :class:`datetime.time` objects for the latter. :issue:`1142`
- Add type hints to tests directory functions. :issue:`938`
- Update to Contributor Covenant 3.0 Code of Conduct, hosted at https://pycal.org/code-of-conduct/.

New features
~~~~~~~~~~~~

- Added :class:`~icalendar.cal.lazy.LazyCalendar` for lazy parsing of subcomponents. :issue:`158`, :issue:`1050`
- Updated :func:`icalendar.prop.dt.time.vTime.from_ical` to support parsing time values with TZID parameters, returning timezone-aware :class:`datetime.time` objects. :issue:`1142`
- Added ``subcomponents`` parameter to :meth:`Component.new <icalendar.cal.component.Component.new>`, :meth:`Event.new <icalendar.cal.event.Event.new>`, :meth:`Todo.new <icalendar.cal.todo.Todo.new>`, and :meth:`Availability.new <icalendar.cal.availability.Availability.new>`. :issue:`1065`
- Switch to uv for development. :issue:`1102`

Bug fixes
~~~~~~~~~

- Allow lenient parsing of content lines with optional whitespace around property and parameter delimiters (for example, ``REFRESH - INTERVAL; VALUE = DURATION:PT48H``) when parsing calendars with ``strict=False``. :issue:`351`
- X-properties with a ``VALUE`` parameter are now parsed using the correct type instead of falling back to :class:`~icalendar.prop.unkown.vUnknown`. :issue:`1238`
- Test that the ``DURATION`` property catches :class:`datetime.timedelta` objects without vProperty wrappers. :issue:`884`
- Fixed :func:`~icalendar.attr.get_end_property` to avoid allowing the creating of VEVENT components with negative durations. Only VTODO components are allowed to have negative durations. :issue:`999`
- GitHub Actions: conditional tests now show as "skipped" instead of "pending". :issue:`1264`
- Fixed :meth:`Component.__eq__ <icalendar.cal.component.Component.__eq__>` method not being commutative when comparing subcomponents. :issue:`1224`
- Verified that the ``VALUE`` parameter of jCal components is used for the type of the component property. :issue:`1237`
- Fix :func:`~icalendar.parser.string.escape_char` handling of ``bytes`` input by converting with :func:`icalendar.parser_tools.to_unicode` before escaping. :issue:`1226`
- Fixed ``RecursionError`` in ``walk()``, ``property_items()``, and ``to_ical()`` by using iterative implementations for component traversal and property extraction. :pr:`1348`

Documentation
~~~~~~~~~~~~~

- Convert docstring of :func:`~icalendar.param.string_parameter` to Google style. :issue:`1072`, :pr:`1316`
- Run ``sphinx-build`` with ``-W`` to turn warnings into errors. :issue:`1306`
- Added `sphinx-llms-txt <https://sphinx-llms-txt.readthedocs.io/en/stable/>`_ extension to generate :file:`llms.txt` and :file:`llms-full.txt` files for AI/LLM documentation consumption. :issue:`1302`
- Fixed CI Vale check reporting and resolved Vale errors. :issue:`1277`
- Include :file:`Makefile` in documentation workflow path filters so documentation CI runs when Makefile logic changes, and keep Vale failures visible in CI output. :issue:`1277`
- Document how to install icalendar on Alpine Linux. :pr:`1290`
- Add documentation for usage of the Sphinx extension `sphinx-icalendar <https://sphinx-icalendar.readthedocs.io/en/latest/>`_. :pr:`1268`
- Add Repology badge and distribution installation instructions to install documentation. :issue:`1119`
- Updated references to :class:`~icalendar.prop.uri.vUri` and :class:`~icalendar.enums.RELTYPE` classes in :file:`attr.py`. :issue:`1158`
- Convert docstrings in :file:`attr.py` and :file:`cal/calendar.py` to Google Style format. :issue:`1072`
- Explained import shortcuts in :doc:`../explanation/api-design` documentation. :issue:`1161`
- Added tutorial for creating a calendar with events with attendees. :pr:`1262`
- Added recognition of NLnet Foundation for its funding and Open Collective for donations to the documentation footer. :issue:`1214`
- Documented ``vText`` properties according to :rfc:`5545#section-3.3.11`. :issue:`742`
- Convert docstrings in :mod:`icalendar.caselessdict` to Google Style format with ``Parameters``, ``Returns``, ``Raises``, and ``Example`` sections as appropriate. :issue:`1072`
- Fix broken docstring for :meth:`~icalendar.cal.component.Component.add_component` link in :attr:`~icalendar.cal.availability.Availability.available`. :issue:`1158`
- Revise AI policy, per NLnet advice. See discussion under `pycal.org issue #24 <https://github.com/pycalendar/pycal.org/issues/24>`_.
- Add documentation for how to use uv for development. :issue:`1102`
- Reorganize Design documentation. :issue:`1292`
- Improve docstring for ``categories_property``, which renders to HTML in :attr:`Calendar.categories <icalendar.cal.calendar.Calendar.categories>`, :attr:`Event.categories <icalendar.cal.event.Event.categories>`, :attr:`Journal.categories <icalendar.cal.journal.Journal.categories>`, and :attr:`Todo.categories <icalendar.cal.todo.Todo.categories>`. :issue:`1244`
- Fixed Python object cross-references in ``icalendar.cal.component.Component._infer_value_type``. :issue:`1158`, :pr:`1344`

7.0.3 (2026-03-03)
------------------

Minor changes
~~~~~~~~~~~~~

- Show colorful required code changes in the CI output to help contributors solve the formatting issues. :pr:`1216`
- Use ruff 0.15.0 for code formatting in :file:`tox.ini`. :pr:`1215`

New features
~~~~~~~~~~~~

- Added :attr:`Event.RECURRENCE_ID <icalendar.cal.event.Event.RECURRENCE_ID>`, :attr:`Todo.RECURRENCE_ID <icalendar.cal.todo.Todo.RECURRENCE_ID>`, and :attr:`Journal.RECURRENCE_ID <icalendar.cal.journal.Journal.RECURRENCE_ID>` properties, including support in their ``new()`` constructors. :issue:`1231`

Bug fixes
~~~~~~~~~

- Fixed :func:`~icalendar.timezone.tzid.tzids_from_tzinfo` not recognizing
  ``dateutil.tz.win.tzwin`` objects on Windows. UTC datetimes using
  ``dateutil.tz.gettz("UTC")`` now correctly serialize with the ``Z`` suffix
  instead of ``TZID=Coordinated Universal Time``. :issue:`1056`
- Fixed :meth:`Calendar.get_missing_tzids <icalendar.cal.calendar.Calendar.get_missing_tzids>`
  raising ``KeyError`` when a VTIMEZONE exists for a timezone not referenced by any event TZID,
  for example, when added by the ``x-wr-timezone`` conversion. :issue:`1124`
- Fixed :meth:`Calendar.get_missing_tzids <icalendar.cal.calendar.Calendar.get_missing_tzids>`
  and :meth:`Calendar.add_missing_timezones <icalendar.cal.calendar.Calendar.add_missing_timezones>`
  generating a spurious ``VTIMEZONE`` for UTC. :rfc:`5545#section-3.2.19` requires UTC datetimes
  to use the ``Z`` suffix; no ``VTIMEZONE`` component is needed or permitted. :issue:`1124`
- Fixed :meth:`Parameters.update_tzid_from <icalendar.parser.parameter.Parameters.update_tzid_from>`
  incorrectly setting ``TZID=UTC`` on UTC datetimes. :rfc:`5545#section-3.2.19` requires UTC datetimes to
  use the ``Z`` suffix without a ``TZID`` parameter. :issue:`1124`
- Renamed the public functions ``escape_char`` and ``unescape_char`` to implicit private methods ``_escape_char`` and ``_unescape_char``
  Fixed regression from :issue:`1008` by restoring :func:`~icalendar.parser.string.escape_char` and :func:`~icalendar.parser.string.unescape_char` as public functions.
  The public functions :func:`~icalendar.parser.string.escape_char` and :func:`~icalendar.parser.string.unescape_char` are now deprecated with warnings for external users.
  :pr:`1241`

Documentation
~~~~~~~~~~~~~

- Add ``icalendar`` as a local workspace dependency to the ``docs`` dependency group in :file:`pyproject.toml` to fix dependency resolution issues with ``uv lock`` during documentation builds. :issue:`1253` :pr:`1254`
- Use ``sphinx-icalendar`` to add syntax highlighting to iCalendar text

7.0.2 (2026-02-24)
------------------

Minor changes
~~~~~~~~~~~~~

- Show required code changes in the CI output to help contributors solve the formatting issues. :pr:`1216`
- Use ruff 0.15.0 for code formatting in :file:`tox.ini`. :pr:`1215`

New features
~~~~~~~~~~~~

- Enabled :meth:`Calendar.from_ical <icalendar.cal.calendar.Calendar.from_ical>` to read calendars from files. :issue:`756`
- Added :attr:`Calendar.journals <icalendar.cal.calendar.Calendar.journals>` property to retrieve all journal components. :issue:`1230`

Documentation
~~~~~~~~~~~~~

- Removed methods of ``str``, ``int``, and other classes and methods in the Python standard library from the documentation.

7.0.1 (2026-02-17)
------------------

Minor changes
~~~~~~~~~~~~~

- Setting :attr:`~cal.calendar.Calendar.calendar_name` now also writes ``X-WR-CALNAME``, and setting :attr:`~cal.calendar.Calendar.description` now also writes ``X-WR-CALDESC``, for improved client compatibility. :issue:`918`

Bug fixes
~~~~~~~~~

- Make ``typing_extensions`` a dependency. :issue:`1202`

Documentation
~~~~~~~~~~~~~

- Fixed the version switcher on Read the Docs, and documented the process for a major release. :issue:`1194`
- Added usage examples for reading calendars from files and URL. :issue:`756`
- Add type hints and convert docstrings to Google Style in :file:`cli.py`. :issue:`938`


7.0.0 (2026-02-11)
------------------

Minor changes
~~~~~~~~~~~~~

- Created an :meth:`~cal.todo.Todo.example` method for the :class:`~cal.todo.Todo` component. :issue:`743`
- Created an :meth:`~cal.alarm.Alarm.example` method for the :class:`~cal.alarm.Alarm` component. :issue:`743`
- Move property classes from :mod:`icalendar.prop` into their own files with sub-packages :mod:`icalendar.prop.recur` and :mod:`icalendar.prop.dt`. :issue:`987`
- Move classes and functions in :mod:`icalendar.parser` into their own files. :issue:`987`
- Clarified custom component (X-* and IANA-registered) parsing behavior through enhanced documentation and comprehensive how-to guide. Custom components are automatically handled by the library with no special configuration required. :issue:`432`
- Reorganized custom component tests into a dedicated :file:`test_custom_components.py` file with expanded test coverage for :meth:`Component.from_ical <icalendar.cal.component.Component.from_ical>`, :meth:`Calendar.from_ical <icalendar.cal.calendar.Calendar.from_ical>`, and :class:`~icalendar.cal.component_factory.ComponentFactory` usage. :issue:`433`
- The ``typing-extensions`` dependency on Python < 3.13 is now optional, part of the ``test`` extra.
- The :func:`icalendar.tools.is_pytz_dt` return value is now hinted as ``TypeGuard[datetime]``, not ``TypeIs[datetime]``, since returning ``False`` should not allow narrowing it as non-datetime.
- Regroup dependencies in, and remove obsolete ones, from :file:`pyproject.toml`. :issue:`906`
- Add type hints to internal helper functions. :issue:`938`
- Add type hints to prop value classes (vBoolean, vFloat, vUri, vBinary, vInline). :issue:`938`
- Add type hints to remaining prop value classes (vText, vCalAddress, vCategory, vGeo, vN, vOrg, vAdr, vBroken, vUid, Conference, Image). :issue:`938`
- Added type hints and overloads to :meth:`Calendar.from_ical <icalendar.cal.calendar.Calendar.from_ical>` and :meth:`Component.from_ical <icalendar.cal.component.Component.from_ical>` to support ``multiple=True/False`` return types. :issue:`1129`
- CI: Print a link to Vale documentation when the spell checker fails.
- Remove :file:`bootstrap.py` and :file:`buildout.cfg` files as they are old build configurations. :pr:`1171`
- Enforce ruff formatting and linting across the entire codebase, with CI check to prevent regressions.
  :issue:`672`, :pr:`1171`, :pr:`1172`, :pr:`1173`, :pr:`1174`, :pr:`1175`, :pr:`1176`, :pr:`1177`, :pr:`1178`, :pr:`1179`, :pr:`1180`, and :pr:`1181`
- Fix type annotations, typos, and validation logic in prop module: corrected return type hints in ``parse_jcal_value`` methods, fixed ``to_ical()`` return type in vDDDTypes, updated ClassVar type hint in TypesFactory, removed dead code, fixed "abbrevation" typo in vWeekday, and corrected validation logic in vMonth. :issue:`1185`
- Rename :class:`~icalendar.prop.vBrokenProperty` to :class:`~icalendar.prop.vBroken` to match naming convention. :class:`~icalendar.prop.vBroken` now stores the actual exception object in ``parse_error`` instead of a string, and raises :class:`~icalendar.error.BrokenCalendarProperty` when accessing attributes like ``.dt`` that the expected type would have. :issue:`1087`

Breaking changes
~~~~~~~~~~~~~~~~

- Drop support for Python 3.8 and 3.9. :issue:`977`
- ``DURATION_REGEX`` moved from :mod:`icalendar.prop` to :mod:`icalendar.prop.dt.duration`. :issue:`987`
- ``WEEKDAY_RULE`` moved from :mod:`icalendar.prop` to :mod:`icalendar.prop.recur.weekday`. :issue:`987`
- Removed ``tzid_from_dt`` and ``tzid_from_tzinfo`` from :mod:`icalendar.prop` as they exist in :mod:`icalendar.timezone`. :issue:`987`
- :meth:`Component.decoded` now returns a string instead of bytes for text properties.
- Remove constants ``FOLD``, ``NAME``, ``NEWLINE``, ``QUNSAFE_CHAR``, ``QUOTABLE``, ``UFOLD``, and ``UNSAFE_CHAR`` from :mod:`icalendar.parser`'s export. :issue:`987`

New features
~~~~~~~~~~~~

- Added ``recursive`` parameter to :meth:`Component.copy` to control copying of subcomponents and properties. :issue:`899`
- Event components now have error-tolerant property parsing. Properties with parsing errors fall back to :class:`~icalendar.prop.vBroken`, preserving the raw value and allowing access to other valid properties. Errors are recorded in ``component.errors``. Partially addresses :issue:`158`
- Added :class:`~icalendar.prop.AdrFields` and :class:`~icalendar.prop.NFields` named tuples for structured access to vCard ADR and N property fields. The ``fields`` attribute and ``from_ical()`` return value of :class:`~icalendar.prop.vAdr` and :class:`~icalendar.prop.vN` now return these typed named tuples, enabling access like ``adr.fields.street`` and ``n.fields.family``. Since named tuples are tuple subclasses, existing code using tuple indexing or unpacking remains compatible. Added ``name`` and ``units`` properties to :class:`~icalendar.prop.vOrg` for convenient access to the organization name and organizational units. Added ``ical_value`` property to all three classes. :issue:`1060`
- Added ``with_uid`` method to ``Component`` to filter subcomponents by UID. :issue:`950`
- Enforce linting of code with Ruff in CI. :issue:`672`

Bug fixes
~~~~~~~~~

- Fixed :meth:`Calendar.new <icalendar.cal.calendar.Calendar.new>` to automatically generate a UID when not provided, matching the documented behavior. Previously, the documentation stated that ``uid`` would be set to a new :func:`uuid.uuid4` if ``None``, but the implementation did not generate it. :issue:`1066`
- Fixed import failure in Pyodide/WebAssembly environments by using lazy initialization for timezone data in the zoneinfo provider. The library can now be imported in environments without timezone data (e.g., Cloudflare Workers, PyScript, JupyterLite). :issue:`1073`
- Fixed :meth:`icalendar.caselessdict.CaselessDict.__eq__` to return ``NotImplemented`` when comparing with non-dict types instead of raising ``AttributeError``. :issue:`1016`
- Fixed decoding of categories. :issue:`279`
- Link ``timedelta`` to :py:class:`datetime.timedelta` in the Python standard library documentation. :issue:`951`
- Fix round-trip parsing of :class:`~icalendar.prop.vCategory` (CATEGORIES property) when category values contain commas. Categories like ``'Meeting, John'`` now correctly survive round trips between :meth:`Component.to_ical <icalendar.cal.component.Component.to_ical>` and :meth:`Component.from_ical <icalendar.cal.component.Component.from_ical>` instead of being split into multiple categories. Added :func:`~icalendar.parser.split_on_unescaped_comma` helper function. :issue:`127`
- Fixed semicolon escaping in vCard structured properties (ADR, N, ORG). Semicolons are now correctly treated as field separators per :rfc:`6350`, not escaped as in iCalendar TEXT values. Added :func:`~icalendar.parser.split_on_unescaped_semicolon` helper function and :class:`~icalendar.prop.vAdr`, :class:`~icalendar.prop.vN`, :class:`~icalendar.prop.vOrg` property types. :issue:`137`
- Fix :meth:`Image.from_property_value <icalendar.prop.image.Image.from_property_value>` to raise ``TypeError`` instead of ``AttributeError`` when ``value.params`` isn't valid (most notably, isn't dict-like). :issue:`909`

Documentation
~~~~~~~~~~~~~

- Improved docstrings and formatting for the :class:`~icalendar.alarms.AlarmTime` class. :issue:`1072`
- Added how-to guide for handling parsing errors with :class:`~icalendar.prop.vBroken` and the ``component.errors`` attribute. :issue:`1085`
- Updated 11 function docstrings in :mod:`icalendar.parser` to follow the Google Style guide, improving API documentation clarity and consistency. :issue:`1072`
- Applied Google-style docstrings to :mod:`icalendar.tools` utility functions with Args, Returns, and Example sections. :issue:`1072`
- Simplify contributors and add supporters in credits. :issue:`1035`
- Add a section in the change log for Documentation. :issue:`1043`
- Fixed multiple ``more than one target found for cross-reference`` warnings, and stopped using ``sphinx.ext.autosectionlabel``, in documentation. :issue:`952`
- Add ``funding.json`` manifest for funding information. :issue:`1047`
- Resolved ``Cannot resolve forward reference in type annotations`` warning in documentation.
  Added ``SPHINX_APIDOC_OPTIONS`` to ``make apidoc`` command, excluding ``__all__`` items from being duplicated in the documentation, and rebuilt the API documentation source files.
  :issue:`952`
- Document how to create and read attendee information in events. :issue:`130`
- Add usage examples. :issue:`443`
- Improve documentation contribution guide by adding chapters for small edits, builds and checks, and a style guide. Added details for Vale usage, Diátaxis framework, narrative and API documentation, and fixing all spelling errors. :issue:`991`
- Document dictionary and property accessors. :issue:`124`
- Moved content from the README into documentation to reduce maintenance and point to the authoritative source of information.
  :issue:`1006`
- Added "Code conventions" section to the Development contributing guide.
  :issue:`1004`
- Use Google style docstrings in :mod:`~icalendar.parser_tools`
  :issue:`1017`
- Document compatibility of icalendar with RFCs. :issue:`1147`
- Added Upgrade guide. :issue:`997`
- Fixed links in jCal usage documentation.
- Enable sphinx-issues extension. :issue:`1091`
- Replaced "Arguments" and "Args" with "Parameters". :issue:`1076`
- Added documentation of how to set up a development environment with git. :issue:`906`
- Documented how to install and use pre-commit. :issue:`996`
- Added a new rule to our docstring style guide to escape docstrings, and added a new section for type hints in the code conventions section. :issue:`1080`
- Documented ``__init__`` methods. :issue:`1079`
- Moved "Edit this page" link to above the page table of contents. :issue:`1106`
- Added Good First Issue link and fixed Up For Grabs link in Contribute guide. :issue:`1095`
- Updated ``CONTRIBUTING.rst`` to explicitly state not to use Args sections in docstrings. :issue:`1076`
- Document ``vInt.__new__`` method parameters in class docstring with :rfc:`5545` examples. :issue:`1118`
- Improved ``make vale`` command to provide guidance on failure or success. :issue:`1137`
- Add ``sphinx_copybutton`` configuration to exclude line numbers, prompts, and console output when copying code blocks.
- Change Sphinx configuration to convert ``--`` to en dash ``-``, ``---`` to em dash ``—``, and ``...`` to ellipsis ``…``, but doesn't transform quote marks as they should be preserved.
  This restores cleaner and consistent rendering of docstrings in the :doc:`API Reference <../reference/api/icalendar>`.
  See `smartquotes_action <https://www.sphinx-doc.org/en/master/usage/configuration.html#confval-smartquotes_action>`_.
- Fix incorrect return type annotation in :meth:`Component.from_ical <icalendar.cal.component.Component.from_ical>`. :issue:`1141`
- Fixed broken links in ``docs/how-to/usage.rst`` documentation. Part of :issue:`1158`
- Enhanced the first-time contributors section, in hopes that fewer contributors ask permission before starting work. :issue:`1165`
- Changed Sphinx configuration to inherit from ``CaselessDict``, displaying all of its class members in the in-page navigation.
  Fixed broken cross-component links in ``Availability.new()``. :issue:`994`
- Configured Sphinx to append the docstring from the ``__init__`` method into its class docstring. :issue:`1156`

7.0.0a3 (2025-12-19)
--------------------

Minor changes
~~~~~~~~~~~~~

- Add static ``[project.urls]`` to ``pyproject.toml`` for GitHub dependency graph compatibility. :issue:`1035`
- Created an :meth:`~cal.todo.Todo.example` method for the :class:`~cal.todo.Todo` component. :issue:`743`
- Add type hints to :mod:`icalendar.caselessdict` file. :issue:`938`
- For releases, added a step to update the version switcher for documentation.

New features
~~~~~~~~~~~~

- Added contributor list format and sorting instructions.

Bug fixes
~~~~~~~~~

- Fix double-unescaping in :meth:`vText.from_ical` and :meth:`vCategory.from_ical` by removing ``unescape_char()``. :issue:`1008`

7.0.0a2 (2025-11-29)
--------------------

Minor changes
~~~~~~~~~~~~~

- Convert changelog section labels to reStructuredText subheadings for improved Read the Docs navigation. :issue:`982`
- Move sections in Table of Content of Reference guide.
- Improve :py:class:`icalendar.prop.vDatetime` documentation. :issue:`946`
- CLI now writes output files using UTF-8 explicitly instead of relying on the system default. :issue:`1005`

New features
~~~~~~~~~~~~

- Add compatibility to :rfc:`9253`:

  - Add new property types :class:`vUid` and :class:`vXmlReference`
  - Add properties to all components: :attr:`Component.concepts`, :attr:`Component.links`, :attr:`Component.refids`, :attr:`Component.related_to`
  - Add new values to :class:`RELTYPE`
  - Add ``LABEL``, ``GAP``, and ``VALUE`` parameters to property values affected by :rfc:`9253`

- Allow setting default values in :class:`Parameters`
- Allow ``None`` as an argument to :class:`Parameters`
- Add ``ical_value`` to several property values. :issue:`876`
- Add PyData Theme version switcher to documentation. :issue:`825`
- Test compatibility with Python 3.14. :issue:`973`
- Added documentation of Vale usage for icalender documentation style guide. :issue:`815`
- Added funding link to :file:`pyproject.toml`.  :issue:`800`
- Added documentation of docstring format. :issue:`747`
- Add ``TypeAlias`` ``icalendar.VPROPERTY`` as a type for all properties.
- Allow access to :class:`icalendar.TypesFactory` via :func:`icalendar.TypesFactory.instance`
- Classes in :mod:`icalendar.prop` can all be initialized with parameters now.
- Allow passing :class:`icalendar.vDDDTypes` as arguments to :class:`icalendar.vDDDLists`
- Add support for :class:`datetime.timezone` identification.
- Add :func:`icalendar.is_utc` to check if a timezone is UTC.
- Add support for JCal parsing and serialization. :issue:`978`

  - Add :class:`icalendar.JCalParsingError` exception for jCal parsing.
  - Add :attr:`icalendar.Parameters.tzid` and :func:`icalendar.Parameters.is_utc` for timezone handling.
  - Add :class:`icalendar.vUnknown` which is the default now for unknown properties and the same as :class:`icalendar.vText`
  - Add :func:`icalendar.ComponentFactory.get_component_class` that also creates a new component class when it does not exist.
  - Add :func:`icalendar.ComponentFactory.add_component_class` to have a unified interface to add component classes.
  - Add :func:`icalendar.Component.to_json`, :func:`icalendar.Component.to_jcal`, and :func:`icalendar.Component.from_jcal` methods so all components can be serialized and parsed.
  - Classes in :mod:`icalendar.prop` receive the following updates:

    - Add ``to_jcal`` and ``from_jcal`` for serialization.
    - Add ``default_value`` class attribute for the default ``VALUE`` parameter.
    - Add ``VALUE`` parameter property.
    - Add ``examples()`` classmethod that returns examples for testing.

- Added documentation of how to fuzz icalendar. :issue:`905`
- Added first-time contributors section to Contributing. :issue:`934`
- Revised check of which files trigger a documentation build on Read the Docs. :issue:`848`
- Created a separate path to contribute to documentation. :issue:`929`
- Added a code of conduct. :issue:`907`
- Added redirects of moved files and 404 not found page to catch any other obsolete URLs. :issue:`959`
- Added artificial intelligence (AI) policy. :issue:`933`


Bug fixes
~~~~~~~~~

- Correct ``name`` of ``AVAILABLE`` component.
- Fix ical serialization of :class:`icalendar.vTime`
- Make sure a component's ``conferences`` property adds ``VALUE=URI`` if the conference is created as a URI.
- Fix CLI deprecated :py:class:`argparse.FileType` usage and remove ``PendingDeprecationWarning``. :issue:`1005`.

6.3.2 (2025-11-03)
------------------

Minor changes
~~~~~~~~~~~~~

- Add PyData Theme version switcher to documentation. See :issue:`825`.

5.0.14 (2025-11-03)
-------------------

Minor changes
~~~~~~~~~~~~~

- Add PyData Theme version switcher to documentation. See :issue:`825`.

4.1.2 (2025-11-03)
------------------

Minor changes
~~~~~~~~~~~~~

- Add PyData Theme version switcher to documentation. See :issue:`825`.

7.0.0a1 (28-10-2025)
--------------------

Minor changes
~~~~~~~~~~~~~

- Split up ``cal.py`` into different files as sub-package.
- Format more source code with ruff.
- Exclude type checking block from test coverage.
- Add private ``icalendar.compatibility`` module to merge functionality for older Python versions into one place.
- Add type annotation to ``from_ical()``.
- Fix enum documentation.
- ``DTSTAMP``, ``LAST_MODIFIED``, and ``CREATED`` can now be set to ``None`` to delete the value.
- Enhanced ``Calendar.new()`` to support organization and language parameters for automatic ``PRODID`` generation.
- Added ``duration`` setter to ``Event`` class for more intuitive event creation.
- Added ``validate()`` method to ``Calendar`` class for explicit validation of required properties and components.
- Add improved setters for ``start``, ``duration``, and ``end`` properties with explicit locking mechanisms to provide more flexible property manipulation while maintaining RFC 5545 compliance. The implementation includes comprehensive test coverage to ensure proper behavior and backward compatibility.
- Add ``new()`` method to ``vCalAddress`` class for consistent API usage. The method supports all RFC 5545 parameters including ``CN``, ``CUTYPE``, ``DELEGATED-FROM``, ``DELEGATED-TO``, ``DIR``, ``LANGUAGE``, ``PARTSTAT``, ``ROLE``, ``RSVP``, and ``SENT-BY``, with automatic ``mailto:`` prefix handling. See :issue:`870`.
- Refactor ``set_duration`` methods in ``Event`` and ``Todo`` classes to eliminate code duplication by extracting common logic into shared ``set_duration_with_locking()`` function in ``icalendar.attr``. See :issue:`886`.
- Consolidate duplicate logic patterns between ``Event`` and ``Todo`` classes by extracting shared functions in ``icalendar.attr`` for property setters, validation logic, and property access. This eliminates approximately 150 lines of duplicate code while maintaining 100% backward compatibility and RFC 5545 compliance. See :issue:`891`.
- Accept and ignore non-standard empty ``RDATE`` fields when parsing ICS files.
- Improve contributing documentation by adding a change log requirement, adding a pull request template, adding clear CI enforcement warnings, and updating ``README.rst``. See :issue:`890`.
- Make coverage submission optional for CI.
- Bump ``actions/setup-python`` version from 5 to 6 for CI.
- Add comment explaining tzdata dependency purpose to prevent confusion. See :issue:`900`.
- Fix duplicate blank issue template by adding config.yml to disable GitHub's default blank option. See :issue:`777`.
- Add PEP 561 py.typed marker to enable type checking support. The package now distributes inline type annotations for mypy and other type checkers. See :issue:`395`.
- Bump ``github/codeql-action`` from 3 to 4 in CI fuzzing workflow.
- Add docstring for ``vDatetime``. See :issue:`742`.
- Update LICENSE file heading formatting.
- Document ``icalendar.version`` module.
- Use ``CONTRIBUTING.md`` in favour of ``.rst`` file.
- Add type hints to ``icalendar.tools`` module.
- Fix more examples link failed in ``README.md`` by renewing its link. See :issue:`958`.
- Fix Contributing, Changelog, License links failed in ``README.md`` by renewing its link. See :issue:`959`.
- Fix more examples link in ``README.md``. See :issue:`958`.
- Add ``CODEOWNERS`` file for automatic pull request review assignment. See :issue:`945`.

Breaking changes
~~~~~~~~~~~~~~~~

- Correctly throw a ``TypeError`` for wrong types during property creation where a ``ValueError`` was thrown before.
- Move ``types_factory`` into ``Component.types_factory``
- Move ``components_factory`` into ``Component.get_component_class``
- Move ``icalendar.cal.IncompleteComponent`` error into ``icalendar.error``.
- Remove ``icalendar.UIDGenerator``. Use Python's built-in `uuid library <https://docs.python.org/3/library/uuid.html>`_ instead.

New features
~~~~~~~~~~~~

- Add ``new()`` to ``icalendar.Calendar`` to set required attributes. See :pr:`569`.
- Add ``new()`` to ``Alarm``, ``Event``, ``Todo``, ``FreeBusy``, ``Component``, and ``Journal`` components. See :issue:`843`.
- Add ``value`` to ``Parameters`` to access the ``VALUE`` parameter.
- Add ``Availability`` and ``Available`` components from :rfc:`7953`. See :issue:`654` and :issue:`864`.
- Add ``stamp``, ``last_modified``, ``created``, ``CREATED``, ``busy_type``, ``class``, ``comments``, ``contacts``, ``location``, ``organizer``, ``priority``, and ``url`` properties to components that use them.
- Add ``availabilities`` attribtue to ``Calendar``.
- Add ``status``, ``transparency``, and ``attendees`` properties. See :issue:`841`.
- Add ``uid`` property that is ``''`` by default and set automatically with ``new()``. See :issue:`315`.
- Make icalendar compatible with `RFC 7986 <https://www.rfc-editor.org/rfc/rfc7986.html>`_.
- Add ``url``, ``source``, ``refresh_interval``, ``conferences``, and ``images`` properties to components.
- Add ``td`` property to ``vDDDTypes`` to make it compatible with ``timedelta`` value types.
- Add documentation for how to install icalendar on Fedora. See :issue:`704`.
- Add documentation linkchecker to make and CI configuration. See :issue:`854`.
- Add support for Vale as spell and style checker.
- For ``make livehtml`` watch all files in ``src/icalendar``, but ignore ``.typed`` and contents of the ``tests`` and ``fuzzing`` directories. See :issue:`931`.
- Restructure documentation, following Diátaxis framework. See :issue:`820` which included the following tasks.

  - Start building API Reference documentation.
  - Add Vale with Microsoft Writing Guide style checker.
  - Add :file:`Makefile` to automate all documentation builds with a single command for each.
  - Write documentation of how to build documentation.
  - Move "History" into "Credits".
  - Add a Glossary of terms.
  - Add version module to API reference.
  - Exclude private Python methods and test modules from the API reference.
  - Fix display of credits to use reStructuredText.
  - Fix the documentation version display.
  - Show older versions of documentation on Read the Docs.
  - Fix the PyPI icon.
  - Add a Security Policy.
  - Consolidate Contributing files into the how-to Contributing guide.
  - Move the change log into the Reference guide.
  - Remove all rights reserved from the License file and remove from documentation, leaving it in the repository root.
  - Move Maintenance into the Contribute guide.
  - Move icalendar contributors into the Contribute guide.
  - Merge about the project into Credits.
  - Split :file:`api.rst` into separate modules.
  - Move "icalendar utility" into a how-to guide for command line interface.
  - Move "icalendar package" into a how-to usage guide and API reference guide.
  - Split installation into how-to guides for usage and contributing.
  - Redesigned home page to reflect the new structure and point readers to the proper location.
  - Fix various Sphinx build warnings and errors.
  - Use text for lexer of ical files.
  - Update :file:`README.rst` to align with new documentation structure.
  - Add documentation builds to continuous integration.
  - Review pull requests that involve source docstrings, continuous integration, or documentation, and provide suggestions and corrections.
- Add spell checking to documentation. See :issue:`853`.
- Add link check to docs test. See :issue:`854`.
- Document installation of icalendar on Fedora. See :issue:`704`.
- Miscellaneous documentation follow-up fixes. See :issue:`919`.

Bug fixes
~~~~~~~~~

- Fix ``Todo.end`` to return ``start`` for date-only ``DTSTART`` (not ``start + 1 day``). Events keep existing behavior. See :issue:`898`.
- Fix ``AssertionError`` when converting ``VTIMEZONE`` components with only ``DAYLIGHT`` subcomponent (no ``STANDARD``) to pytz timezones. The code now handles cases where a timezone definition contains only DST transitions by calculating the DST offset from ``TZOFFSETFROM`` and ``TZOFFSETTO``. Test case contributed by @niccokunzmann in :pr:`379`. See :issue:`321`.
- Normalize Conference parameter lists (FEATURE/LABEL/LANGUAGE) to comma-separated values. See :issue:`908`.
- Fix read from stdin issue - See :issue:`821`.
- Fix invalid calendar: Parsing a date with TZID results in a datetime to not loose the timezone. See :issue:`187`.
- Fix timezone placement in ``add_missing_timezones()``: ``VTIMEZONE`` components now appear before ``VEVENT`` and other components that reference them. See :issue:`844`.
- Fixed ``Todo.duration`` and ``Event.duration`` to return ``DURATION`` property when set, even without ``DTSTART``. See :issue:`867`.
- Fix ``VALUE`` parameter handling: ``datetime.date`` objects now correctly set ``VALUE=DATE`` parameter when added to properties like ``EXDATE``, ``RDATE``, and ``DTSTART``. The ``VALUE`` parameter is also properly used when parsing iCalendar data. See :issue:`349`.
- Fix URL-encoded characters being incorrectly unescaped during content line parsing. The parser now properly handles backslash escaping and double-quoted sections without corrupting URL-encoded values like ``%3A`` (colon) in DESCRIPTION fields. Added ``unescape_backslash()`` function to separate :rfc:`5545` backslash escaping from URL encoding. Optimized implementation using regex for single-pass processing. Added type hints to ``Contentline.parts()`` method and comprehensive unit tests. See :issue:`355`.
- `make livehtml` now reloads with code changes. See :issue:`931`.
- Added tests for tools, vFloat, vBinary, vGeo, and vTodo to improve unit test coverage. :issue:`698`


6.3.1 (2025-05-20)
------------------

Bug fixes
~~~~~~~~~

- Remove forced quoting from parameters with space and single quote. See :issue:`836`.

6.3.0 (2025-05-15)
------------------

Minor changes
~~~~~~~~~~~~~

- Deprecate ``icalendar.UIDGenerator``. See :issue:`816`.

New features
~~~~~~~~~~~~

- Add the ``uid`` property to ``Alarm``, ``Event``, ``Calendar``, ``Todo``, and ``Journal`` components. See :issue:`740`.

Bug fixes
~~~~~~~~~

- Fix component equality where timezones differ for the datetimes but the times are actually equal. See :issue:`828`.
- Test that we can add an RRULE as a string. See :issue:`301`.
- Test that we support dateutil timezones as outlined in :issue:`336`.
- Build documentation on Read the Docs with the version identifier. See :issue:`826`.

6.2.0 (2025-05-07)
------------------

Minor changes
~~~~~~~~~~~~~

- Use ``ruff`` to format the source code.
- Update project metadata to use License-Expression.
- Use ``tzp.localize(dt, None)`` to remove the timezone from a datetime.
- Remove the HTML documentation when building with ``tox`` to force rebuild.
- Switch to PyData Sphinx Theme for documentation. See :pr:`803`.

New features
~~~~~~~~~~~~

- Add getters ``rrules``, ``rdates``, and ``exdates`` for unified and simple access to these properties. See `Discussion 662`_.
- Add attributes to the calendar for properties ``NAME``, ``DESCRIPTION``, and ``COLOR``. See :issue:`655`.
- Add a ``color`` attribute to ``Event``, ``Todo``, and ``Journal`` components. See :issue:`655`.
- Add ``sequence`` attribute to ``Event``, ``Todo``, and ``Journal`` components. See :issue:`802`.
- Add ``categories`` attribute to ``Calendar``, ``Event``, ``Todo``, and ``Journal`` components. See :issue:`655`.
- Add compatibility to :rfc:`6868`. See :issue:`652`.
- Add ``freebusy`` property to the ``Calendar`` to get this type of subcomponents easier.
- Add parameters from :rfc:`5545` to properties ``ALTREP``, ``CN``, ``CUTYPE``, ``DELEGATED_FROM``, ``DELEGATED_TO``, ``DIR``, ``FBTYPE``, ``LANGUAGE``, ``MEMBER``, ``PARTSTAT``, ``RANGE``, ``RELATED``, ``ROLE``, ``RSVP``, ``SENT_BY``, ``TZID``, and ``RELTYPE``. See :issue:`798`.
- New properties from :rfc:`7986` can occur multiple times in ``VCALENDAR``. See :pr:`808`.

Bug fixes
~~~~~~~~~

- Fix ``STANDARD`` and ``DAYLIGHT`` components that have a date as ``DTSTART``. See :issue:`218`
- Move import at the end of ``icalendar.parser`` into a function to mitigate import errors, see :issue:`781`.
- ``ALTREP``, ``DELEGATED-FROM``, ``DELEGATED-TO``, ``DIR``, ``MEMBER``, and ``SENT-BY`` require double quotes. These are now always added.
- Classify ``CATEGORIES`` as multiple in ``VEVENT``. See :pr:`808`.

6.1.3 (2025-03-19)
------------------

Bug fixes
~~~~~~~~~

- Fix to permit TZID forward references to ``VTIMEZONE``\ s
- Stabelize timezone id lookup, see :issue:`780`.

6.1.2 (2025-03-19)
------------------

Minor changes
~~~~~~~~~~~~~

- Add funding link to Tidelift.
- Link to related package.
- Shorten first example in documentation.
- Add ``name`` and ``email`` properties to ``vCalAddress``.
- Add type hint for property ``params`` in ``icalendar.prop``.
- Set default value for ``params`` as ``params={}`` in mulitple constructors in ``icalendar.prop`` to improve usability.
- Improve object initialization performance in ``icalendar.prop``.
- Add type hint for ``params`` in multiple constructors in ``icalendar.prop``.

Bug fixes
~~~~~~~~~

- Restrict timezones tested, see :issue:`763`

6.1.1 (2025-01-18)
------------------

Minor changes
~~~~~~~~~~~~~

- Add a ``weekday`` attribute to :class:`icalendar.prop.vWeekday` components. See :issue:`749`.
- Document :class:`icalendar.prop.vRecur` property. See :issue:`758`.
- Print failure of doctest to aid debugging.
- Improve documentation of :class:`icalendar.prop.vGeo`
- Fix tests, improve code readability, fix typing. See :pr:`766` and :pr:`765`.

Breaking changes
~~~~~~~~~~~~~~~~

- The ``relative`` attribute of ``vWeekday`` components has the correct sign now. See :issue:`749`.

New features
~~~~~~~~~~~~

- Add `Security Policy <https://github.com/collective/icalendar/blob/main/SECURITY.md>`_
- Python types in documentation now link to their documentation pages using ``intersphinx``.

6.1.0 (2024-11-22)
------------------

Minor changes
~~~~~~~~~~~~~

- Add ``end``, ``start``, ``duration``, ``DTSTART``, ``DUE``, and ``DURATION`` attributes to ``Todo`` components. See `Discussion 662`_.
- Add ``DTSTART``, ``TZOFFSETTO`` and ``TZOFFSETFROM`` properties to ``TimezoneStandard`` and ``TimezoneDaylight``. See `Discussion 662`_.
- Format test code with Ruff. See :issue:`672`.
- Document the Debian package. See :issue:`701`.
- Document ``vDatetime.from_ical``
- Allow passing a ``datetime.date`` to ``TZP.localize_utc`` and ``TZP.localize`` methods.
- Document component classes with description from :rfc:`5545`.
- Merge "File Structure" and "Overview" sections in the docs. See :issue:`626`.
- Update code blocks in ``usage.rst`` with the correct lexer.
- Tidy up the docstring for ``icalendar.prop.vPeriod``.
- Improve typing and fix typing issues


New features
~~~~~~~~~~~~

- Add ``VALARM`` properties for :rfc:`9074`. See :issue:`657`
- Test compatibility with Python 3.13
- Add ``Timezone.from_tzinfo()`` and ``Timezone.from_tzid()`` to create a ``Timezone`` component from a ``datetime.tzinfo`` timezone. See :issue:`722`.
- Add ``icalendar.prop.tzid_from_tzinfo``.
- Add ``icalendar.alarms`` module to calculate alarm times. See :issue:`716`.
- Add ``Event.alarms`` and ``Todo.alarms`` to access alarm calculation.
- Add ``Component.DTSTAMP`` and ``Component.LAST_MODIFIED`` properties for datetime in UTC.
- Add ``Component.is_thunderbird()`` to check if the component uses custom properties by Thunderbird.
- Add ``X_MOZ_SNOOZE_TIME`` and ``X_MOZ_LASTACK`` properties to ``Event`` and ``Todo``.
- Add ``Alarm.ACKNOWLEDGED``, ``Alarm.TRIGGER``, ``Alarm.REPEAT``, and ``Alarm.DURATION`` properties
  as well as ``Alarm.triggers`` to calculate alarm triggers.
- Add ``__doc__`` string documentation for ``vDate``, ``vBoolean``, ``vCalAddress``, ``vDuration``, ``vFloat``, ``vGeo``, ``vInt``, ``vPeriod``, ``vTime``, ``vUTCOffset`` and ``vUri``. See :issue:`742`.
- Add ``DTSTART``, ``TZOFFSETTO``, and ``TZOFFSETFROM`` to ``TimezoneStandard`` and ``TimezoneDaylight``
- Use ``example`` methods of components without arguments.
- Add ``events``, ``timezones``, and ``todos`` property to ``Calendar`` for nicer access.
- To calculate which timezones are in use and add them to the ``Calendar`` when needed these methods are added: ``get_used_tzids``, ``get_missing_tzids``, and ``add_missing_timezones()``.
- Identify the TZID of more timezones from dateutil.
- Identify totally unknown timezones using a UTC offset lookup tree generated in ``icalendar.timezone.equivalent_timezone_ids`` and stored in ``icalendar.timezone.equivalent_timezone_ids``.
- Add ``icalendar.timezone.tzid`` to identify a timezone's TZID.

Bug fixes
~~~~~~~~~

- Add ``icalendar.timezone`` to the documentation.


6.0.1 (2024-10-13)
------------------

New features
~~~~~~~~~~~~

- Added ``end``, ``start``, ``duration``, ``DTSTART``, ``DUE``, and ``DURATION`` attributes to ``Event`` components. See `Discussion 662`_.
- Added ``end``, ``start``, ``duration``, and ``DTSTART`` attributes to ``Journal`` components. See `Discussion 662`_.

Bug fixes
~~~~~~~~~

- Fix a few ``__all__`` variables.
- Added missing ``docs`` folder to distribution packages. See :issue:`712`.

.. _`Discussion 662`: https://github.com/collective/icalendar/discussions/662

6.0.0 (2024-09-28)
------------------

Minor changes
~~~~~~~~~~~~~

- Add ``__all__`` variable to each modules in ``icalendar`` package
- Improve test coverage.
- Adapt ``test_with_doctest.py`` to correctly run on Windows.
- Measure branch coverage when running tests.
- Export ``Component`` base class for typing

New features
~~~~~~~~~~~~

- Use ``pyproject.toml`` file instead of ``setup.py``

Bug fixes
~~~~~~~~~

- Fix link to stable release of tox in documentation.
- Fix a bad ``bytes`` replace in ``unescape_char``.
- Handle ``ValueError`` in ``vBinary.from_ical``.
- Ignore the BOM character in incorrectly encoded ics files.

6.0.0a0 (2024-07-03)
--------------------

Minor changes
~~~~~~~~~~~~~

- Test that all code works with both ``pytz`` and ``zoneinfo``.
- Add message to GitHub release, pointing to the changelog
- Make coverage report submission optional for pull requests
- Parallelize coverage
- Rename ``master`` branch to ``main``, see `Issue
  <https://github.com/collective/icalendar/issues/627>`_
- Update ``docs/usage.rst`` to use zoneinfo instead of pytz.
- Added missing public classes and functions to API documentation.
- Improved namespace management in the ``icalendar`` directory.
- Add Python version badge and badge for test coverage
- Remove 4.x badge
- Update list of ``tox`` environments
- Use Coveralls' GitHub Action
- Check distribution in CI

Breaking changes
~~~~~~~~~~~~~~~~

- Use ``zoneinfo`` for ``icalendar`` objects created from strings,
  see :issue:`609`.

  This is an tested extension of the functionality, not a restriction:
  If you create ``icalendar`` objects with ``pytz`` timezones in your code,
  ``icalendar`` will continue to work in the same way.
  Your code is not affected.

  ``zoneinfo`` will be used for those **objects that** ``icalendar``
  **creates itself**.
  This happens for example when parsing an ``.ics`` file, strings or bytes with
  ``from_ical()``.

  If you rely on ``icalendar`` providing timezones from ``pytz``, you can add
  one line to your code to get the behavior of versions below 6:

  .. code:: Python

      import icalendar
      icalendar.use_pytz()

- Replaced ``pkg_resources.get_distribution`` with ``importlib.metadata`` in
  ``docs/conf.py`` to allow building docs on Python 3.12.

- Remove ``is_broken`` property. Use ``errors`` instead to check if a
  component had suppressed parsing errors.
  See :issue:`424`.

- Remove untested and broken ``LocalTimezone`` and ``FixedOffset`` tzinfo
  sub-classes, see :issue:`67`

- Remove Python 3.7 as compatible. icalendar is compatible with Python
  versions 3.8 - 3.12, and PyPy3.

- Remove ``pytz`` as a dependency of ``icalendar``. If you require ``pytz``,
  add it to your dependency list or install it additionally with::

      pip install icalendar==6.* pytz

New features
~~~~~~~~~~~~

- Check code quality with `Ruff <https://docs.astral.sh/ruff/>`_, optional report
- Test compatibility with Python 3.12
- Add function ``icalendar.use_pytz()``.
- Allows selecting components with ``walk(select=func)`` where ``func`` takes a
  component and returns ``True`` or ``False``.
- Add compatibility to :rfc:`7529`, adding ``vMonth`` and ``vSkip``
- Add ``sphinx-autobuild`` for ``livehtml`` Makefile target.
- Add pull request preview on Read the Docs, building only on changes to documentation-related files.
- Add link to pull request preview builds in the pull request description only when there are changes to documentation-related files.
- Add documentation of live HTML preview of documentation and clean up of ``install.rst``.
- Add ``sphinx-copybutton`` to allow copying code blocks with a single click of a button.

Bug fixes
~~~~~~~~~

- Change documentation to represent compatibility with Python 3.8 - 3.12, and PyPy3.
- Rename RFC 2445 to RFC 5545, see `Issue 278
  <https://github.com/collective/icalendar/issues/278>`_

5.0.13 (2024-06-20)
-------------------

Minor changes
~~~~~~~~~~~~~

- Guide to delete the build folder before running tests
- Add funding information
- Make documentation build with Python 3.12
- Update windows to olson conversion for Greenland Standard Time
- Extend examples in Usage with alarm and recurrence
- Document how to serve the built documentation to view with the browser
- Improve test coverage

New features
~~~~~~~~~~~~

- Create GitHub releases for each tag.

Bug fixes
~~~~~~~~~

- Parse calendars with X-COMMENT properties at the end the file by ignoring these properites


5.0.12 (2024-03-19)
-------------------

Minor changes
~~~~~~~~~~~~~

- Analyse code coverage of test files
- Added corpus to fuzzing directory
- Added exclusion of fuzzing corpus in MANIFEST.in
- Augmented fuzzer to optionally convert multiple calendars from a source string
- Add script to convert OSS FUZZ test cases to Python/pytest test cases
- Added additional exception handling of defined errors to fuzzer, to allow fuzzer to explore deeper
- Added more instrumentation to fuzz-harness
- Rename "contributor" to "collaborator" in documentation
- Correct the outdated "icalendar view myfile.ics" command in documentation. #588
- Update GitHub Actions steps versions
- Keep GitHub Actions up to date with GitHub's Dependabot

Bug fixes
~~~~~~~~~

- Fixed index error in cal.py when attempting to pop from an empty stack
- Fixed type error in prop.py when attempting to join strings into a byte-string
- Caught Wrong Date Format in ical_fuzzer to resolve fuzzing coverage blocker

5.0.11 (2023-11-03)
-------------------

Minor changes
~~~~~~~~~~~~~

- The cli utility now displays start and end datetimes in the user's local timezone.
  Ref: #561
  [vimpostor]

New features
~~~~~~~~~~~~

- Added fuzzing harnesses, for integration to OSSFuzz.
- icalendar releases are deployed to Github releases
  Fixes: #563
  [jacadzaca]

Bug fixes
~~~~~~~~~

- CATEGORIES field now accepts a string as argument
  Ref: #322
  [jacadzaca]
- Multivalue FREEBUSY property is now parsed properly
  Ref: #27
  [jacadzaca]
- Compare equality and inequality of calendars more completely
  Ref: #570
- Use non legacy timezone name.
  Ref: #567
- Add some compare functions.
  Ref: #568
- Change OSS Fuzz build script to point to harnesses in fuzzing directory
  Ref: #574

5.0.10 (2023-09-26)
-------------------

Bug fixes
~~~~~~~~~

- Component._encode stops ignoring parameters argument on native values, now merges them
  Fixes: #557
  [zocker1999net]

5.0.9 (2023-09-24)
------------------

Bug fixes
~~~~~~~~~

- PERIOD values now set the timezone of their start and end. #556

5.0.8 (2023-09-18)
------------------

Minor changes
~~~~~~~~~~~~~

- Update build configuration to build readthedocs. #538
- No longer run the ``plone.app.event`` tests.
- Add documentation on how to parse ``.ics`` files. #152
- Move pip caching into Python setup action.
- Check that issue #165 can be closed.
- Updated about.rst for issue #527
- Avoid ``vText.__repr__`` BytesWarning.

Bug fixes
~~~~~~~~~

- Calendar components are now properly compared
  Ref: #550
  Fixes: #526
  [jacadzaca]

5.0.7 (2023-05-29)
------------------

Bug fixes
~~~~~~~~~

- to_ical() now accepts RRULE BYDAY values>=10 #518


5.0.6 (2023-05-26)
------------------

Minor changes
~~~~~~~~~~~~~

- Adjusted duration regex

5.0.5 (2023-04-13)
------------------

Minor changes
~~~~~~~~~~~~~

- Added support for BYWEEKDAY in vRecur ref: #268

Bug fixes
~~~~~~~~~

- Fix problem with ORGANIZER in FREE/BUSY #348

5.0.4 (2022-12-29)
------------------

Minor changes
~~~~~~~~~~~~~

- Improved documentation
  Ref: #503, #504

Bug fixes
~~~~~~~~~

- vBoolean can now be used as an parameter
  Ref: #501
  Fixes: #500
  [jacadzaca]


5.0.3 (2022-11-23)
------------------

New features
~~~~~~~~~~~~

- vDDDTypes is hashable #487 #492 [niccokunzmann]

Bug fixes
~~~~~~~~~

- vDDDTypes' equality also checks the dt attribute #497 #492 [niccokunzmann]

5.0.2 (2022-11-03)
------------------

Minor changes
~~~~~~~~~~~~~

- Refactored cal.py, tools.py and completed remaining minimal refactoring in parser.py. Ref: #481 [pronoym99]
- Calendar.from_ical no longer throws long errors
  Ref: #473
  Fixes: #472
  [jacadzaca]
- Make datetime value shorter by removing the value parameter where possible.
  Fixes: #318
  [jacadzaca], [niccokunzmann]

New features
~~~~~~~~~~~~

- source code in documentation is tested using doctest #445 [niccokunzmann]

Bug fixes
~~~~~~~~~

- broken properties are not added to the parent component
  Ref: #471
  Fixes: #464
  [jacadzaca]

5.0.1 (2022-10-22)
------------------

Minor changes
~~~~~~~~~~~~~

- fixed setuptools deprecation warnings [mgorny]

Bug fixes
~~~~~~~~~

- a well-known timezone timezone prefixed with a `/` is treated as if the slash wasn't present
  Ref: #467
  Fixes: #466
  [jacadzaca]

5.0.0 (2022-10-17)
------------------

Minor changes
~~~~~~~~~~~~~

- removed deprecated test checks [tuergeist]
- Fix: cli does not support DURATION #354 [mamico]
- Add changelog and contributing to readthedocs documentation #428 [peleccom]
- fixed small typos #323 [rohnsha0]
- unittest to parametrized pytest refactoring [jacadzaca]

Breaking changes
~~~~~~~~~~~~~~~~

- Require Python 3.7 as minimum Python version.  [maurits] [niccokunzmann]
- icalendar now takes a ics file directly as an input
- icalendar's CLI utility program's output is different
- Drop Support for Python 3.6. Versions 3.7 - 3.11 are supported and tested.

New features
~~~~~~~~~~~~

- icalendar utility outputs a 'Duration' row
- icalendar can take multiple ics files as an input

Bug fixes
~~~~~~~~~

- Changed tools.UIDGenerator instance methods to static methods
  Ref: #345
  [spralja]
- proper handling of datetime objects with `tzinfo` generated through zoneinfo.ZoneInfo.
  Ref: #334
  Fixes: #333
  [tobixen]
- Timestamps in UTC does not need tzid
  Ref: #338
  Fixes: #335
  [tobixen]
-  add ``__eq__`` to ``icalendar.prop.vDDDTypes`` #391 [jacadzaca]
- Refactor deprecated unittest aliases for Python 3.11 compatibility #330 [tirkarthi]

5.0.0a1 (2022-07-11)
--------------------

Breaking changes
~~~~~~~~~~~~~~~~

- Drop support for Python 3.4, 3.5 and PyPy2.  [maurits]

New features
~~~~~~~~~~~~

- Document development setup
  Ref: #358
  [niccokunzmann]

Bug fixes
~~~~~~~~~

- Test with GitHub Actions.  [maurits]

4.1.0 (2022-07-11)
------------------

New features
~~~~~~~~~~~~

- No longer test on Python 3.4, 3.5 and PyPy2, because we cannot get it to work.
  Technically it should still work, it is just no longer tested.
  Do not expect much development on branch 4.x anymore.
  The main branch will be for the remaining Python versions that we support.
  [maurits]

Bug fixes
~~~~~~~~~

- Test with GitHub Actions.  [maurits]

4.0.9 (2021-10-16)
------------------

Bug fixes
~~~~~~~~~

- Fix vCategories for correct en/de coding.
  [thet]

- vDuration property value: Fix changing duration sign after multiple ``to_ical`` calls.
  Ref: #320
  Fixes: #319
  [barlik]


4.0.8 (2021-10-07)
------------------

Bug fixes
~~~~~~~~~

- Support added for Python 3.9 and 3.10 (no code changes needed).

- Replace bare 'except:' with 'except Exception:' (#281)


4.0.7 (2020-09-07)
------------------

Bug fixes
~~~~~~~~~

- fixed rrule handling, re-enabled test_create_america_new_york()


4.0.6 (2020-05-06)
------------------

Bug fixes
~~~~~~~~~

- Use ``vText`` as default type, when convert recurrence definition to ical string. [kam193]

4.0.5 (2020-03-21)
------------------

Bug fixes
~~~~~~~~~

- Fixed a docs issue related to building on Read the Docs [davidfischer]

4.0.4 (2019-11-25)
------------------

Bug fixes
~~~~~~~~~

- Reduce Hypothesis iterations to speed up testing, allowing PRs to pass
  [UniversalSuperBox]


4.0.3 (2018-10-10)
------------------

Bug fixes
~~~~~~~~~

- Categories are comma separated not 1 per line #265. [cleder]
- mark test with mixed timezoneaware and naive datetimes as an expected failure. [cleder]


4.0.2 (2018-06-20)
------------------

Bug fixes
~~~~~~~~~

- Update all pypi.python.org URLs to pypi.org
  [jon.dufresne]


4.0.1 (2018-02-11)
------------------

- Added rudimentary command line interface.
  [jfjlaros]

- Readme, setup and travis updates.
  [jdufresne, PabloCastellano]


4.0.0 (2017-11-08)
------------------

Breaking changes
~~~~~~~~~~~~~~~~

- Drop support for Python 2.6 and 3.3.


3.12 (2017-11-07)
-----------------

New features
~~~~~~~~~~~~

- Accept Windows timezone identifiers as valid. #242 [geier]

Bug fixes
~~~~~~~~~

- Fix ResourceWarnings in setup.py when Python warnings are enabled. #244 [jdufresne]

- Fix invalid escape sequences in string and bytes literals. #245 [jdufresne]

- Include license file in the generated wheel package. #243 [jdufresne]

- Fix non-ASCII TZID and TZNAME parameter handling. #238 [clivest]

- Docs: update install instructions. #240 [Ekran]


3.11.7 (2017-08-27)
-------------------

New features
~~~~~~~~~~~~

- added vUTCOffset.ignore_exceptions to allow surpressing of failed TZOFFSET
  parsing (for now this ignores the check for offsets > 24h) [geier]


3.11.6 (2017-08-04)
-------------------

Bug fixes
~~~~~~~~~

- Fix ``VTIMEZONE``\ s including RDATEs #234.  [geier]


3.11.5 (2017-07-03)
-------------------

Bug fixes
~~~~~~~~~

- added an assertion that ``VTIMEZONE`` sub-components' DTSTART must be of type
  DATETIME [geier]

- Fix handling of ``VTIMEZONE``\ s with subcomponents with the same DTSTARTs and
  OFFSETs but which are of different types  [geier]


3.11.4 (2017-05-10)
-------------------

Bug fixes
~~~~~~~~~

- Don't break on parameter values which contain equal signs, e.g. base64 encoded
  binary data [geier]

- Fix handling of ``VTIMEZONE``\ s with subcomponents with the same DTSTARTs.
  [geier]


3.11.3 (2017-02-15)
-------------------

Bug fixes
~~~~~~~~~

- Removed ``setuptools`` as a dependency as it was only required by setup.py
  and not by the package.

- Don't split content lines on the unicode ``LINE SEPARATOR`` character
  ``\u2028`` but only on ``CRLF`` or ``LF``.

3.11.2 (2017-01-12)
-------------------

Bug fixes
~~~~~~~~~

- Run tests with python 3.5 and 3.6.
  [geier]

- Allow tests failing with pypy3 on travis.ci.
  [geier]


3.11.1 (2016-12-19)
-------------------

Bug fixes
~~~~~~~~~

- Encode error message before adding it to the stack of collected error messages.


3.11 (2016-11-18)
-----------------

Fixes:

- Successfully test with pypy and pypy3.  [gforcada]

- Minor documentation update.  [tpltnt]


3.10 (2016-05-26)
-----------------

New:

- Updated components description to better comply with RFC 5545.
  Refs #183.
  [stlaz]

- Added PERIOD value type to date types.
  Also fixes incompatibilities described in #184.
  Refs #189.
  [stlaz]

Fixes:

- Fix testsuite for use with ``dateutil>=2.5``.
  Refs #195.
  [untitaker]

- Reintroduce cal.Component.is_broken that was removed with 3.9.2.
  Refs #185.
  [geier]


3.9.2 (2016-02-05)
------------------

New:

- Defined ``test_suite`` in setup.py.
  Now tests can be run via ``python setup.py test``.
  [geier]

Fixes:

- Fixed cal.Component.from_ical() representing an unknown component as one of the known.
  [stlaz]

- Fixed possible IndexError exception during parsing of an ical string.
  [stlaz]

- When doing a boolean test on ``icalendar.cal.Component``, always return ``True``.
  Before it was returning ``False`` due to CaselessDict, if it didn't contain any items.
  [stlaz]

- Fixed date-time being recognized as date or time during parsing.
  Added better error handling to parsing from ical strings.
  [stlaz]

- Added __version__ attribute to init.py.
  [TomTry]

- Documentation fixes.
  [TomTry]

- Pep 8, UTF 8 headers, dict/list calls to literals.
  [thet]


3.9.1 (2015-09-08)
------------------

- Fix ``vPeriod.__repr__``.
  [spacekpe]

- Improve foldline() performance. This improves the foldline performance,
  especially for large strings like base64-encoded inline attachements. In some
  cases (1MB string) from 7 Minutes to less than 20ms for ASCII data and 500ms
  for non-ASCII data. Ref: #163.
  [emfree]


3.9.0 (2015-03-24)
------------------

- Creating timezone objects from ``VTIMEZONE`` components.
  [geier]

- Make ``python-dateutil`` a dependency.
  [geier]

- Made RRULE tolerant of trailing semicolons.
  [sleeper]

- Documentation fixes.
  [t-8ch, thet]

3.8.4 (2014-11-01)
------------------

- Add missing BYWEEKNO to recurrence rules.
  [russkel]


3.8.3 (2014-08-26)
------------------

- PERCENT property in VTODO renamed to PERCENT-COMPLETE, according to RFC5545.
  [thomascube]


3.8.2 (2014-07-22)
------------------

- Exclude editor backup files from egg distributions. Fixes #144.
  [thet]


3.8.1 (2014-07-17)
------------------

- The representation of CaselessDicts in 3.8 changed the name attribute of
  Components and therefore broke the external API. This has been fixed.
  [untitaker]


3.8 (2014-07-17)
----------------

- Allow dots in property names (Needed for vCard compatibility). Refs #143.
  [untitaker]

- Change class representation for CaselessDict objects to always include the
  class name or the class' name attribute, if available. Also show
  subcomponents for Component objects.
  [thet]

- Don't use data_encode for CaselessDict class representation but use dict's
  __repr__ method.
  [t-8ch]

- Handle parameters with multiple values, which is needed for vCard 3.0.
  Refs #142.
  [t-8ch]


3.7 (2014-06-02)
----------------

- For components with ``ignore_exceptions`` set to ``True``, mark unparseable
  lines as broken instead rising a ``ValueError``. ``VEVENT`` components have
  ``ignore_exceptions`` set to ``True`` by default. Ref #131. Fixes #104.
  [jkiang13]

- Make ``python-dateutil`` a soft-dependency.
  [boltnev]

- Add optional ``sorted`` parameter to ``Component.to_ical``. Setting it to
  false allows the user to preserve the original property and parameter order.
  Ref #136. Fixes #133.
  [untitaker]

- Fix tests for latest ``pytz``. Don't set ``tzinfo`` directly on datetime
  objects, but use pytz's ``localize`` function. Ref #138.
  [untitaker, thet]

- Remove incorrect use of __all__. We don't encourage using ``from package
  import *`` imports. Fixes #129.
  [eric-wieser]


3.6.2 (2014-04-05)
------------------

- Pep8 and cleanup.
  [lasudry]

3.6.1 (2014-01-13)
------------------

- Open text files referenced by setup.py as utf-8, no matter what the locale
  settings are set to. Fixes #122.
  [sochotnicky]

- Add tox.ini to source tarball, which simplifies testing for in distributions.
  [sochotnicky]


3.6 (2014-01-06)
----------------

- Python3 (3.3+) + Python 2 (2.6+) support [geier]

- Made sure to_ical() always returns bytes [geier]

- Support adding lists to a component property, which value already was a list
  and remove the Component.set method, which was only used by the add method.
  [thet]

- Remove ability to add property parameters via a value's params attribute when
  adding via cal.add (that was only possible for custom value objects and makes
  up a strange API), but support a parameter attribute on cal.add's method
  signature to pass a dictionary with property parameter key/value pairs.
  Fixes #116.
  [thet]

- Backport some of Regebro's changes from his regebro-refactor branch.
  [thet]

- Raise explicit error on another malformed content line case.
  [hajdbo]

- Correctly parse datetime component property values with timezone information
  when parsed from ical strings.
  [untitaker]


3.5 (2013-07-03)
----------------

- Let to_unicode be more graceful for non-unicode strings, as like CMFPlone's
  safe_unicode does it.
  [thet]


3.4 (2013-04-24)
----------------

- Switch to unicode internally. This should fix all en/decoding errors.
  [thet]

- Support for non-ascii parameter values. Fixes #88.
  [warvariuc]

- Added functions to transform chars in string with '\\' + any of r'\,;:' chars
  into '%{:02X}' form to avoid splitting on chars escaped with '\\'.
  [warvariuc]

- Allow seconds in vUTCOffset properties. Fixes #55.
  [thet]

- Let ``Component.decode`` better handle vRecur and vDDDLists properties.
  Fixes #70.
  [thet]

- Don't let ``Component.add`` re-encode already encoded values. This simplifies
  the API, since there is no need explicitly pass ``encode=False``. Fixes #82.
  [thet]

- Rename tzinfo_from_dt to tzid_from_dt, which is what it does.
  [thet]

- More support for dateutil parsed tzinfo objects. Fixes #89.
  [leo-naeka]

- Remove python-dateutil version fix at all. Current python-dateutil has Py3
  and Py2 compatibility.
  [thet]

- Declare the required python-dateutil dependency in setup.py. Fixes #90.
  [kleink]

- Raise test coverage.
  [thet]

- Remove interfaces module, as it is unused.
  [thet]

- Remove ``test_doctests.py``, test suite already created properly in
  ``test_icalendar.py``.
  [rnix]

- Transformed doctests into unittests, Test fixes and cleanup.
  [warvariuc]


3.3 (2013-02-08)
----------------

- Drop support for Python < 2.6.
  [thet]

- Allow vGeo to be instantiated with list and not only tuples of geo
  coordinates. Fixes #83.
  [thet]

- Don't force to pass a list to vDDDLists and allow setting individual RDATE
  and EXDATE values without having to wrap them in a list.
  [thet]

- Fix encoding function to allow setting RDATE and EXDATE values and not to
  have bypass encoding with an icalendar property.
  [thet]

- Allow setting of timezone for vDDDLists and support timezone properties for
  RDATE and EXDATE component properties.
  [thet]

- Move setting of TZID properties to vDDDTypes, where it belongs to.
  [thet]

- Use @staticmethod decorator instead of wrapper function.
  [warvariuc, thet]

- Extend quoting of parameter values to all of those characters: ",;: â'".
  This fixes an outlook incompatibility with some characters. Fixes: #79,
  Fixes: #81.
  [warvariuc]

- Define VTIMETZONE subcomponents STANDARD and DAYLIGHT for RFC5545 compliance.
  [thet]


3.2 (2012-11-27)
----------------

- Documentation file layout restructuring.
  [thet]

- Fix time support. vTime events can be instantiated with a datetime.time
  object, and do not inherit from datetime.time itself.
  [rdunklau]

- Correctly handle tzinfo objects parsed with dateutil. Fixes #77.
  [warvariuc, thet]

- Text values are escaped correclty. Fixes #74.
  [warvariuc]

- Returned old folding algorithm, as the current implementation fails in some
  cases. Fixes #72, Fixes #73.
  [warvariuc]

- Supports to_ical() on date/time properties for dates prior to 1900.
  [cdevienne]


3.1 (2012-09-05)
----------------

- Make sure parameters to certain properties propagate to the ical output.
  [kanarip]

- Re-include doctests.
  [rnix]

- Ensure correct datatype at instance creation time in ``prop.vCalAddress``
  and ``prop.vText``.
  [rnix]

- Apply TZID parameter to datetimes parsed from RECURRENCE-ID
  [dbstovall]

- Localize datetimes for timezones to avoid DST transition errors.
  [dbstovall]

- Allow UTC-OFFSET property value data types in seconds, which follows RFC5545
  specification.
  [nikolaeff]

- Remove utctz and normalized_timezone methods to simplify the codebase. The
  methods were too tiny to be useful and just used at one place.
  [thet]

- When using Component.add() to add icalendar properties, force a value
  conversion to UTC for CREATED, DTSTART and LAST-MODIFIED. The RFC expects UTC
  for those properties.
  [thet]

- Removed last occurrences of old API (from_string).
  [Rembane]

- Add 'recursive' argument to property_items() to switch recursive listing.
  For example when parsing a text/calendar text including multiple components
  (e.g. a ``VCALENDAR`` with 5 ``VEVENT``s), the previous situation required us to look
  over all properties in ``VEVENT``s even if we just want the properties under the
  ``VCALENDAR`` component (VERSION, PRODID, CALSCALE, METHOD).
  [dmikurube]

- All unit tests fixed.
  [mikaelfrykholm]


3.0.1b2 (2012-03-01)
--------------------

- For all TZID parameters in DATE-TIME properties, use timezone identifiers
  (e.g. Europe/Vienna) instead of timezone names (e.g. CET), as required by
  RFC5545. Timezone names are used together with timezone identifiers in the
  Timezone components.
  [thet]

- Timezone parsing, issues and test fixes.
  [mikaelfrykholm, garbas, tgecho]

- Since we use pytz for timezones, also use UTC tzinfo object from the pytz
  library instead of own implementation.
  [thet]


3.0.1b1 (2012-02-24)
--------------------

- Update Release information.
  [thet]


3.0
---

- Add API for proper Timezone support. Allow creating ical DATE-TIME strings
  with timezone information from Python datetimes with pytz based timezone
  information and vice versa.
  [thet]

- Unify API to only use to_ical and from_ical and remove string casting as a
  requirement for Python 3 compatibility:
  New: to_ical.
  Old: ical, string, as_string and string casting via __str__ and str.
  New: from_ical.
  Old: from_string.
  [thet]


2.2 (2011-08-24)
----------------

- migration to https://github.com/collective/icalendar using svn2git preserving
  tags, branches and authors.
  [garbas]

- using tox for testing on python 2.4, 2.5, 2.6, 2.6.
  [garbas]

- fixed tests so they pass also under python 2.7.
  [garbas]

- running tests on ``https://jenkins.plone.org/job/icalendar`` (only 2.6 for now)
  with some other metrics (pylint, clonedigger, coverage).
  [garbas]

- review and merge changes from ``https://github.com/cozi/icalendar`` fork.
  [garbas]

- created sphinx documentation and started documenting development and goals.
  [garbas]

- hook out github repository to https://about.readthedocs.com service so sphinx
  documentation is generated on each commit (for main). Documentation can be
  visible on: https://icalendar.readthedocs.io/en/latest/
  [garbas]


2.1 (2009-12-14)
----------------

- Fix deprecation warnings about ``object.__init__`` taking no parameters.

- Set the VALUE parameter correctly for date values.

- Long binary data would be base64 encoded with newlines, which made the
  iCalendar files incorrect. (This still needs testing).

- Correctly handle content lines which include newlines.


2.0.1 (2008-07-11)
------------------

- Made the tests run under Python 2.5+

- Renamed the UTC class to Utc, so it would not clash with the UTC object,
  since that rendered the UTC object unpicklable.


2.0 (2008-07-11)
----------------

- EXDATE and RDATE now returns a vDDDLists object, which contains a list
  of vDDDTypes objects. This is do that EXDATE and RDATE can contain
  lists of dates, as per RFC.

  ***Note!***: This change is incompatible with earlier behavior, so if you
  handle EXDATE and RDATE you will need to update your code.

- When createing a vDuration of -5 hours (which in itself is nonsensical),
  the ical output of that was -P1DT19H, which is correct, but ugly. Now
  it's '-PT5H', which is prettier.


1.2 (2006-11-25)
----------------

- Fixed a string index out of range error in the new folding code.


1.1 (2006-11-23)
----------------

- Fixed a bug in caselessdicts popitem. (thanks to Michael Smith
  <msmith@fluendo.com>)

- The RFC 2445 was a bit unclear on how to handle line folding when it
  happened to be in the middle of a UTF-8 character. This has been clarified
  in the following discussion:
  `[Ietf-calsify] draft-ietf-calsify-rfc2445bis-01.txt / UTF-8 <https://web.archive.org/web/20121209193206/http://lists.osafoundation.org/pipermail/ietf-calsify/2006-August/001126.html>`_.
  And this is now implemented in iCalendar. It will not fold in the middle of
  a UTF-8 character, but may fold in the middle of a UTF-8 composing character
  sequence.


1.0 (2006-08-03)
----------------

- make get_inline and set_inline support non ascii codes.

- Added support for creating a python egg distribution.


0.11 (2005-11-08)
-----------------

- Changed component .from_string to use types_factory instead of hardcoding
  entries to 'inline'

- Changed UTC tzinfo to a singleton so the same one is used everywhere

- Made the parser more strict by using regular expressions for key name,
  param name and quoted/unquoted safe char as per the RFC

- Added some tests from the schooltool icalendar parser for better coverage

- Be more forgiving on the regex for folding lines

- Allow for multiple top-level components on .from_string

- Fix vWeekdays, wasn't accepting relative param (eg: -3SA vs -SA)

- vDDDTypes didn't accept negative period (eg: -P30M)

- 'N' is also acceptable as newline on content lines, per RFC


0.10 (2005-04-28)
-----------------

- moved code to codespeak.net subversion.

- reorganized package structure so that source code is under 'src' directory.
  Non-package files remain in distribution root.

- redid doc/.py files as doc/.txt, using more modern doctest. Before they
  were .py files with big docstrings.

- added test.py testrunner, and tests/test_icalendar.py that picks up all
  doctests in source code and doc directory, and runs them, when typing::

    python2.3 test.py

- renamed iCalendar to lower case package name, lowercased, de-pluralized and
  shorted module names, which are mostly implementation detail.

- changed tests so they generate .ics files in a temp directory, not in the
  structure itself.
