All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

[4.0.0] - Unreleased

This is a major release and is not source or binary compatible with version 3.x.

Please see Version 4 Migration Guide for details about API changes since libical 3.x.

Added

REUSE compliant licensing
Supports multi-valued parameters (DELEGATED-FROM, DELEGATED-TO, MEMBER, DISPLAY, FEATURE, etc)
Adds java bindings
Brand new icalvcard library that follows the libical API.
draft-ietf-calext-eventpub-extensions-19 (RFC 9073) support added
draft-ietf-calext-valarm-extensions-07 (RFC 9074) support added
Added support for Event Publishing (RFC 9073) and VALARM (RFC 9074) Extensions
New CMake option "LIBICAL_ENABLE_64BIT_ICALTIME_T" to use 64-bit time_t implementations on 32-bit systems (where available and supported. Windows-only so far)
GEO property has arbitrary precision (values are internally stored as strings, not doubles)
Allow previous recurrence iteration
icalparser_ctrl setting defines how to handle invalid CONTROL characters during parsing
Full support for BYSETPOS, i.e. remove the limitation to MONTHLY and YEARLY frequencies
An API for setting/getting internal library limits (icallimit_set and icallimit_get)

Changed

Built-in timezones updated to tzdata2025c to include historical data
Requires MSVC 2013 or higher (when building on Windows with MSVC)
Requires CMake v3.20.0 or higher
For the C++ bindings, requires a C++11 compliant C++ compiler
libical-glib requires glib 2.38 or higher
libical-glib requires a C11 compliant C compiler
Replace gtk-doc with gi-docgen to produce libical-glib developer documentation
libical-glib API is considered stable; no longer need to define LIBICAL_GLIB_UNSTABLE_API=1 before including <libical-glib/libical-glib.h>
By default, only shared libraries are built; to get static libraries one must invoke separate build using the CMake -DLIBICAL_STATIC=True option.
CMake option -DGOBJECT_INTROSPECTION=True by default.
icaltzutil_get_zone_directory() can use the TZDIR environment to find system zoneinfo
icaltimezone_set_tzid_prefix() now allows setting an empty tzid prefix.
icaldurationtype_from_int and icaldurationtype_as_int have been renamed to icaldurationtype_from_seconds and icaldurationtype_as_seconds, respectively.
Components and properties with arbitrary iana-token names now are parsed with kind ICAL_IANA_COMPONENT and ICAL_IANA_PROPERTY if the ical_unknown_token_handling setting is ICAL_ASSUME_IANA_TOKEN. Otherwise, they are handled as error.
Property and parameter names that start with "x-" (lowercase) now also are parsed as X kind.
The icalproperty_remove_parameter_by_(kind|name) functions now remove all matching parameters. Before, they only removed the first matching parameter contrary to their documentation.

Deprecated

The icalvcal library is deprecated and will be removed sometime in the 4.x series. Please port your icalvcal code to use icalvcard instead.
Several CMake options are renamed in favor of a "namespaced" equivalent. Please port your buildscripts to the new CMake option names. A complete list is provided in this "CMake options" section of the Version 4 Migration Guide

Removed

The old src/python code is removed in favor of the glib-introspection generated Python bindings. Requires building with -DGOBJECT_INTROSPECTION=True

Fixed

Fixed icalcomponent_get_duration() to account for DTEND/DUE TZID
Improved performance of recurrence iterators
Improved handling of BYWEEKNO when BYDAY is not present
Fixed icalcomponent_get_dtend() and icalcomponent_foreach_recurrence() to correctly handle nominal durations
Fixed icalcomponent_foreach_recurrence to filter out duplicate instances

[3.0.21] - Unreleased

Fix some scenarios with RRULEs and EXRULE (#754)

[3.0.20] - 2025-05-10

Clean up the byte-swapping macros
Fix a testcase in libical-glib when using 64-bit on a 32-bit system
Fix regression introduced in v3.0.19 ignoring non-empty REQUEST-STATUS extdata
Fix regression introduced in v3.0.19 error reporting for END before BEGIN
Fix a CMake problem in libical-glib

[3.0.19] - 2024-12-23

Fix for changes to the libicu 75 API
Add vcpkg manifest-mode support
Improved berkeley-db discovery on Mac with homebrew
Improved libicu discrovery on Mac with homebrew
Properly set DYLD_LIBRARY_PATH on Mac for libical-ical tests
Resolved known limitation: Negative values are now also supported for BYMONTHDAY and BYYEARDAY.
Add support for RDATE;VALUE=PERIOD
Fix time conversion to time_t for times before epoch
Allow icalcomponent_foreach_recurrence to receive DATE-only start and end params.
Fix the calculation of an event's duration if DTSTART is a DATE-only value.
Fix icaltime_span_new() - ignore the case where DTEND is unset and require it to be set by the caller instead.
Various fixes for fuzzer issues

[3.0.18] - 2024-03-24

Requires CMake v3.5.0 or higher
Escape ^ (U+005E) character in parameter values according to RFC 6868
New CMake option LIBICAL_BUILD_EXAMPLES to disable building the examples
Should be able to use the project as a submodule
Built-in timezones updated to tzdata2024a

[3.0.17] - 2023-10-14

Improved Android support
Escape commas in x-property TEXT values
Built-in timezones updated to tzdata2023c
icalparser_ctrl setting defines how to handle invalid CONTROL characters during parsing
New publicly available functions:
- get_zone_directory
- icalparser_get_ctrl
- icalparser_set_ctrl

[3.0.16] - 2022-10-17

Fix regressions in 3.0.15 due to improperly tested fuzz fixes
Fix argument guards in icaltime_as_timet to match documentation and tests

[3.0.15] - 2022-10-06

Add missing property parameters into libical-glib
Fix CMake option USE_32BIT_TIME_T actually uses a 32-bit time_t value
Fix icaltime_as_timet, which returned incorrect results for years >= 2100, to work properly between years 1902 and 10k.
Fix x-property comma handling and escaping
Built-in timezones updated to tzdata2022d (now with a VTIMEZONE for each time zone alias)
Fix a fuzzer issue
Handle unreachable-code compile warnings with clang
Ensure all vanew_foo() calls finish with (void*)0 (not 0)

[3.0.14] - 2022-02-15

icalvalue: Reset non-UTC icaltimetype::zone on set
Fix icalcomponent_set_due not removing TZID when necessary

[3.0.13] - 2022-01-17

icalcomponent_get_dtend() returns icaltime_null_time() unless called on VEVENT, VAVAILABILITY or VFREEBUSY
icalcomponent_get_duration() for VTODO calculate with DUE instead of DTEND
Replace CMake FindBDB with FindBerleyDB (https://github.com/sum01/FindBerkeleyDB)
Fix finding ICU and BerkeleyDB on Mac (look for homebrew installs first)

[3.0.12] - 2021-12-08

Fix a libicalval crash in cleanVObject
METHOD:DECLINECOUNTER must have DTEND or DURATION
Handle if DTEND and DURATION are both missing
Improved FindICU (copied from official CMake. see files in cmake/Kitware)
Buildsystem fixes (especially for the Ninja generator)
Built-in timezones updated to tzdata2021e

[3.0.11] - 2021-10-09

Fix icalrecur_iterator_set_start() for hourly, minutely, and secondly recurrences
Fix build for Berkeley DB version greater than 5
Fix vcal for some architectures (like aarch64, ppc64le and s390x)
Fix memory leaks in vcal
Prevent crash when looking for tzid in initialize_rscale
Adjust libdir and includedir in generated pkgconfig files
Built-in timezones updated to tzdata2021c

[3.0.10] - 2021-04-17

Fix building -DSTATIC_ONLY=True with Ninja
Fix generating wrong recurrence rules (#478)
Fix a bug computing transitions in tzfiles
Fix reading TZif files to use TZ string in the footer as the last (non-terminating) transitions
Fix reading TZif files to use more RRULEs and/or RDATEs whevever possible
Built-in timezones updated to tzdata2021a

[3.0.9] - 2021-01-16

Add support for empty parameters, e.g. CN=""
Accept VTIMEZONE with more than one X- property
Several fixes for recurrences containing BYWEEKNO
icalrecurrencetype_from_string() will reject any RRULE that contains a rule-part that occurs more than once
Improve thread safety
Fix compiled-in path for the built-in timezone data
Fix reading TZif files with empty v1 data (use v2+ whenever possible)
Add backwards compatibility for previous TZIDs
Built-in timezones updated to tzdata2020d
icalrecurrencetype_from_string() will reject any RRULE that contains a rule-part that occurs more than once
Fix build with newer libicu
Fix cross-compile support in libical-glib

[3.0.8] - 2020-03-07

Fix for icalattach_new_from_data() and the 'free_fn' argument
Fix if recurrencetype contains both COUNT and UNTIL (only output UNTIL in the RRULE)

[3.0.7] - 2019-12-15

libical-glib: Fix ICalAttach handling of the icalattach native structure
Let icalattach_new_from_data() use the 'free_fn' argument again
Fix memory leaks in attachment handling and elsewhere
Fix a multithreading race condition
More fuzzification fixes

[3.0.6] - 2019-09-14

Handle both COUNT and UNTIL in RRULEs
Fix RRULE BYDAY with INTERVAL=2 conflict
Various fuzzification fixes
New publicly available function:
- icaltimezone_truncate_vtimezone
Add option to disable building the test suite
Built-in timezones updated to tzdata2019c

[3.0.5] - 2019-05-14

New publicly available function:
- icalproperty_get_datetime_with_component
Allow reset DATE/DATE-TIME VALUE parameter for all-day events
icalproperty_get_datetime_with_component() will use location as TZID fallback.
New CMake option ENABLE_GTK_DOC for disabling the libical-glib developer documentation
GObject Introspection - use $MAJOR-0 versioning
libical-glib API is considered unstable, define LIBICAL_GLIB_UNSTABLE_API=1 before including <libical-glib/libical-glib.h> to be able to use it.
Built-in timezones updated to tzdata2019a
De-fuzzifications and Coverity fixes

[3.0.4] - 2018-08-14

Silently fail RSCALE recurrence clauses when RSCALE is disabled
Fixed icalcomponent_set_comment() and icalcomponent_set_uid()
fix FREQ=MONTHLY;BYMONTH
Skip UTF-8 marker when parsing
Fix parsing "<CR>?<LF>" in VCF files produced by Outlook
Fix TZID on DATE-TIME value can override time specified in UTC
CMake discovery module for ICU uses pkg-config now
New publicly available function:
- icalparameter_kind_is_valid
Built-in timezones updated to tzdata2018e

[3.0.3] - 2018-02-27

VTODO COMPLETED property can be a DATE-TIME or DATE (for backward compatibility)
Improved recurrence iteration

[3.0.2] - 2018-02-17

No longer attempt to detect the need for -DUSE_32BIT_TIME_T with MSVC
New CMake option ICAL_BUILD_DOCS which can be used to disable the docs target
Fix threading hang in BSD type systems (OpenBSD, MacOS,...)
Build with Ninja improvements

[3.0.1] - 2017-11-18

Built-in timezones updated to tzdata2017c
Fix a multi-threaded deadlock in icaltimezone_load_builtin_timezone()
Fix a CMake problem with parallel builds

[3.0.0] - 2017-10-28

Relicense from MPL 1.0 to MPL 2.0 (keep dual license for LGPL v2.1)
Requires CMake v3.1.0 or higher along with various CMake and buildsystem fixes
Added a 'make uninstall'
Fixed use-after-free issues and some memory leaks
Built-in timezones updated to tzdata2017b
More accurate VTIMEZONE generation when using the system time zone data (when USE_BUILTIN_TZDATA=False)
icalvalue_as_ical_string() returns "TRUE" (non-zero) or "FALSE" (zero) values only.
New icalvalue.h convenience macros: ICAL_BOOLEAN_TRUE and ICAL_BOOLEAN_FALSE
Better value type checking of property values when parsing
icalvalue_new/set_date and icalvalue_new/set_datetime now enforce DATE and DATE-TIME values respectively
draft-ietf-calext-extensions (RFC 7986) support added
Parameter values are now en/decoded per RFC 6868
Removed is_utc from icaltimetype struct
- Set icaltimetype.zone to icaltimezone_get_utc_timezone() to change a time to UTC
- Use icaltime_is_utc() to check if a time is in UTC
Added support for VPATCH component
New publicly available functions:
- icalproperty_set_parent (icalproperty_get_parent was already public)
- icalvalue_get_parent (icalvalue_set_parent was already public)
- icalparameter_set_parent
- icalparameter_get_parent
- icalvalue_new_datetimedate (DATE or DATE-TIME)
- icalvalue_set_datetimedate
- icalvalue_get_datetimedate
- icalrecur_iterator_set_start
- icalcomponent_normalize
- icalproperty_normalize
Removed deprecated functions:
- icaltime_from_timet (use icaltime_from_timet_with_zone)
- icaltime_start_day_of_week (use icaltime_start_day_week)
- icalproperty_remove_parameter (use icalproperty_remove_parameter_by_kind)
- icalproperty_string_to_enum (use icalproperty_kind_and_string_to_enum)
Signature changed for functions:
- Parse_MIME_FromFileName
- icalgauge *icalgauge_new_from_sql
- const char *icallangbind_property_eval_string
- const char *icallangbind_property_eval_string_r
- void set_zone_directory
- icalcalendar *icalcalendar_new
- int icalrecur_expand_recurrence

[2.0.0] - 2015-12-28

WARNING: Version 2 IS NOT Binary Compatible with Older Versions
Version 2 is Source Compatible with Older Versions
Lots of source code scrubbing
[New] RSCALE support (requires libicu from http://www.icu-project.org)
[New] CalDAV attachment support (draft-ietf-calext-caldav-attachments)
[New] Resurrect the Berkeley DB storage support
[Bug] issue83: Incorrect recurrence generation for weekly pattern
Handle RRULEs better
Handle threading better

[1.0.1] - 2014-10-11

[Bug] issue74: Do not escape double quote character
[Bug] issue80,issue92: fix crashes using icaltimezone_load_builtin_timezone() recursively
[Bug] Fix icalcomponent_foreach_recurrence() and large durations between recurrences (e.g. FREQ=YEARLY)
[Bug] Properly handle UTCOFFSETs of the form +/-00mmss
[Bug] Properly skip bogus dates (e.g. 2/30, 4/31) in RRULE:FREQ=MONTHLY
[Bug] Properly handle RRULE:FREQ=MONTHLY;BYDAY;BYMONTHDAY when DTSTART isn't on BYDAY
[Bug] Fix RRULE:FREQ=YEARLY;BYDAY;BYWEEKNO - MUST use ISO weeks
[Bug] Properly skip bogus dates (e.g. 2/29) in RRULE:FREQ=YEARLY[;BYMONTH][;BYMONTHDAY]
[New] Update tzdata to version 2014g
[New] Support added for schedule params: agent, status, force-send
[New] Added a UID to the VFREEBUSY component
[New] Allow dates > 2038 if sizeof(time_t) > 4
[New] Add properties from draft-ietf-tzdist-service
[New] Add support for RRULE:FREQ=YEARLY;BYDAY;BYYEARDAY
[New] Fixed RRULE:FREQ=YEARLY;BYYEARDAY for negative days
[Build] Autotools build system is removed
[Build] CMake version 2.8.9 (or higher) is required (was CMake version 2.4.0)
[Build] Add new -DSHARED_ONLY and -DSTATIC_ONLY CMake options
[Build] Remove -DSTATIC_LIBRARY CMake option
[Build] MSYS2 builds (fixed instructions)
[Build/Doc] Now can build api documentation with make docs
[Quality] More regression tests added, in particular for recurrence
[Quality] Almost all compile warnings silenced
[Quality] A bunch of Coverity Scan warnings silenced

[1.0.0] - 2014-06-28

Reborn