Zoneinfo

[niccokunzmann]

This makes a start at #609.

My idea of how to go about it:

• Move all pytz usage into icalendar.timzone.pytz (refactoring)
• Create a abstract base class that is the interface that is used
• Create an alternative implementation for zoneinfo

TODO:

• map localtime timezone of zoneinfo to no timezone in the ics file, see Zoneinfo #623 (comment)
• map Factory timezone to something ??? in the ics file - but what is that timezone?, see Zoneinfo #623 (comment)
• make sure that the transition times are properly computed for custom timezone components, see Zoneinfo #623 (comment)

[coveralls]

Pull Request Test Coverage Report for Build 9480387615

Details

• 703 of 713 (98.6%) changed or added relevant lines in 27 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage decreased (-0.02%) to 96.682%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/icalendar/cal.py	35	36	97.22%
src/icalendar/timezone/init.py	6	7	85.71%
src/icalendar/timezone/pytz.py	36	37	97.3%
src/icalendar/timezone/tzp.py	64	66	96.97%
src/icalendar/timezone/zoneinfo.py	73	75	97.33%
src/icalendar/tests/conftest.py	64	67	95.52%

Files with Coverage Reduction	New Missed Lines	%
src/icalendar/tests/conftest.py	1	95.97%

Totals
Change from base Build 9241523599:	-0.02%
Covered Lines:	3030
Relevant Lines:	3134

---

💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 9366927231

Details

• 32 of 33 (96.97%) changed or added relevant lines in 6 files are covered.
• 6 unchanged lines in 3 files lost coverage.
• Overall coverage decreased (-0.002%) to 96.704%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/icalendar/timezone/provider.py	4	5	80.0%

Files with Coverage Reduction	New Missed Lines	%
src/icalendar/tests/test_cli_tool.py	2	88.0%
src/icalendar/tests/test_timezoned.py	2	99.08%
src/icalendar/tests/conftest.py	2	96.33%

Totals
Change from base Build 9241523599:	-0.002%
Covered Lines:	2787
Relevant Lines:	2882

---

💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 9366927231

Details

• 32 of 33 (96.97%) changed or added relevant lines in 6 files are covered.
• 6 unchanged lines in 3 files lost coverage.
• Overall coverage decreased (-0.002%) to 96.704%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/icalendar/timezone/provider.py	4	5	80.0%

Files with Coverage Reduction	New Missed Lines	%
src/icalendar/tests/test_cli_tool.py	2	88.0%
src/icalendar/tests/test_timezoned.py	2	99.08%
src/icalendar/tests/conftest.py	2	96.33%

Totals
Change from base Build 9241523599:	-0.002%
Covered Lines:	2787
Relevant Lines:	2882

---

💛 - Coveralls

[niccokunzmann]

There are timezones that pytz understands but zoneinfo does not know. How should we go about this?

Details

``` FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_0-localtime] - AssertionError: PYTZ should know localtime FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_0-Factory] - AssertionError: PYTZ should know Factory FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Africa/Asmera] - AssertionError: ZONEINFO should know Africa/Asmera FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-America/Argentina/ComodRivadavia] - AssertionError: ZONEINFO should know America/Argentina/ComodRivadavia FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-America/Buenos_Aires] - AssertionError: ZONEINFO should know America/Buenos_Aires FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-America/Catamarca] - AssertionError: ZONEINFO should know America/Catamarca FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-America/Cordoba] - AssertionError: ZONEINFO should know America/Cordoba FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-America/Fort_Wayne] - AssertionError: ZONEINFO should know America/Fort_Wayne FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-America/Godthab] - AssertionError: ZONEINFO should know America/Godthab FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-America/Indianapolis] - AssertionError: ZONEINFO should know America/Indianapolis FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-America/Jujuy] - AssertionError: ZONEINFO should know America/Jujuy FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-America/Knox_IN] - AssertionError: ZONEINFO should know America/Knox_IN FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-America/Louisville] - AssertionError: ZONEINFO should know America/Louisville FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-America/Mendoza] - AssertionError: ZONEINFO should know America/Mendoza FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-America/Rosario] - AssertionError: ZONEINFO should know America/Rosario FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Antarctica/South_Pole] - AssertionError: ZONEINFO should know Antarctica/South_Pole FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Asia/Ashkhabad] - AssertionError: ZONEINFO should know Asia/Ashkhabad FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Asia/Calcutta] - AssertionError: ZONEINFO should know Asia/Calcutta FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Asia/Chungking] - AssertionError: ZONEINFO should know Asia/Chungking FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Asia/Dacca] - AssertionError: ZONEINFO should know Asia/Dacca FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Asia/Katmandu] - AssertionError: ZONEINFO should know Asia/Katmandu FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Asia/Macao] - AssertionError: ZONEINFO should know Asia/Macao FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Asia/Rangoon] - AssertionError: ZONEINFO should know Asia/Rangoon FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Asia/Saigon] - AssertionError: ZONEINFO should know Asia/Saigon FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Asia/Thimbu] - AssertionError: ZONEINFO should know Asia/Thimbu FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Asia/Ujung_Pandang] - AssertionError: ZONEINFO should know Asia/Ujung_Pandang FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Asia/Ulan_Bator] - AssertionError: ZONEINFO should know Asia/Ulan_Bator FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Atlantic/Faeroe] - AssertionError: ZONEINFO should know Atlantic/Faeroe FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Australia/ACT] - AssertionError: ZONEINFO should know Australia/ACT FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Australia/LHI] - AssertionError: ZONEINFO should know Australia/LHI FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Australia/NSW] - AssertionError: ZONEINFO should know Australia/NSW FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Australia/North] - AssertionError: ZONEINFO should know Australia/North FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Australia/Queensland] - AssertionError: ZONEINFO should know Australia/Queensland FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Australia/South] - AssertionError: ZONEINFO should know Australia/South FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Australia/Tasmania] - AssertionError: ZONEINFO should know Australia/Tasmania FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Australia/Victoria] - AssertionError: ZONEINFO should know Australia/Victoria FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Australia/West] - AssertionError: ZONEINFO should know Australia/West FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Brazil/Acre] - AssertionError: ZONEINFO should know Brazil/Acre FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Brazil/DeNoronha] - AssertionError: ZONEINFO should know Brazil/DeNoronha FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Brazil/East] - AssertionError: ZONEINFO should know Brazil/East FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Brazil/West] - AssertionError: ZONEINFO should know Brazil/West FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Canada/Atlantic] - AssertionError: ZONEINFO should know Canada/Atlantic FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Canada/Central] - AssertionError: ZONEINFO should know Canada/Central FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Canada/Eastern] - AssertionError: ZONEINFO should know Canada/Eastern FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Canada/Mountain] - AssertionError: ZONEINFO should know Canada/Mountain FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Canada/Newfoundland] - AssertionError: ZONEINFO should know Canada/Newfoundland FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Canada/Pacific] - AssertionError: ZONEINFO should know Canada/Pacific FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Canada/Saskatchewan] - AssertionError: ZONEINFO should know Canada/Saskatchewan FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Canada/Yukon] - AssertionError: ZONEINFO should know Canada/Yukon FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Chile/Continental] - AssertionError: ZONEINFO should know Chile/Continental FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Chile/EasterIsland] - AssertionError: ZONEINFO should know Chile/EasterIsland FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Cuba] - AssertionError: ZONEINFO should know Cuba FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Egypt] - AssertionError: ZONEINFO should know Egypt FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Eire] - AssertionError: ZONEINFO should know Eire FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Europe/Kiev] - AssertionError: ZONEINFO should know Europe/Kiev FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Europe/Uzhgorod] - AssertionError: ZONEINFO should know Europe/Uzhgorod FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Europe/Zaporozhye] - AssertionError: ZONEINFO should know Europe/Zaporozhye FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-GB] - AssertionError: ZONEINFO should know GB FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-GB-Eire] - AssertionError: ZONEINFO should know GB-Eire FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-GMT+0] - AssertionError: ZONEINFO should know GMT+0 FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-GMT-0] - AssertionError: ZONEINFO should know GMT-0 FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-GMT0] - AssertionError: ZONEINFO should know GMT0 FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Greenwich] - AssertionError: ZONEINFO should know Greenwich FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Hongkong] - AssertionError: ZONEINFO should know Hongkong FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Iceland] - AssertionError: ZONEINFO should know Iceland FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Iran] - AssertionError: ZONEINFO should know Iran FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Israel] - AssertionError: ZONEINFO should know Israel FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Jamaica] - AssertionError: ZONEINFO should know Jamaica FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Japan] - AssertionError: ZONEINFO should know Japan FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Kwajalein] - AssertionError: ZONEINFO should know Kwajalein FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Libya] - AssertionError: ZONEINFO should know Libya FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Mexico/BajaNorte] - AssertionError: ZONEINFO should know Mexico/BajaNorte FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Mexico/BajaSur] - AssertionError: ZONEINFO should know Mexico/BajaSur FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Mexico/General] - AssertionError: ZONEINFO should know Mexico/General FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-NZ] - AssertionError: ZONEINFO should know NZ FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-NZ-CHAT] - AssertionError: ZONEINFO should know NZ-CHAT FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Navajo] - AssertionError: ZONEINFO should know Navajo FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-PRC] - AssertionError: ZONEINFO should know PRC FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Pacific/Enderbury] - AssertionError: ZONEINFO should know Pacific/Enderbury FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Pacific/Ponape] - AssertionError: ZONEINFO should know Pacific/Ponape FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Pacific/Truk] - AssertionError: ZONEINFO should know Pacific/Truk FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Poland] - AssertionError: ZONEINFO should know Poland FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Portugal] - AssertionError: ZONEINFO should know Portugal FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-ROC] - AssertionError: ZONEINFO should know ROC FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-ROK] - AssertionError: ZONEINFO should know ROK FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Singapore] - AssertionError: ZONEINFO should know Singapore FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Turkey] - AssertionError: ZONEINFO should know Turkey FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-UCT] - AssertionError: ZONEINFO should know UCT FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-US/Alaska] - AssertionError: ZONEINFO should know US/Alaska FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-US/Aleutian] - AssertionError: ZONEINFO should know US/Aleutian FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-US/Arizona] - AssertionError: ZONEINFO should know US/Arizona FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-US/Central] - AssertionError: ZONEINFO should know US/Central FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-US/East-Indiana] - AssertionError: ZONEINFO should know US/East-Indiana FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-US/Eastern] - AssertionError: ZONEINFO should know US/Eastern FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-US/Hawaii] - AssertionError: ZONEINFO should know US/Hawaii FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-US/Indiana-Starke] - AssertionError: ZONEINFO should know US/Indiana-Starke FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-US/Michigan] - AssertionError: ZONEINFO should know US/Michigan FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-US/Mountain] - AssertionError: ZONEINFO should know US/Mountain FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-US/Pacific] - AssertionError: ZONEINFO should know US/Pacific FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-US/Samoa] - AssertionError: ZONEINFO should know US/Samoa FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Universal] - AssertionError: ZONEINFO should know Universal FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-W-SU] - AssertionError: ZONEINFO should know W-SU FAILED src/icalendar/tests/test_pytz_zoneinfo_integration.py::test_timezone_names_are_known[tzp_1-Zulu] - AssertionError: ZONEINFO should know Zulu ```

Fixed:

https://stackoverflow.com/questions/78580391/zoneinfo-is-missing-timezone-names-that-pytz-has/78580486#78580486

Install tzdata

[stevepiercy]

@niccokunzmann I don't feel qualified to merge this one. Let's get at least one qualified person at the sprint to review it.

[niccokunzmann]

@thet This PR is good for me so far. If you have time, your review would be welcome.

Before merge:

• create a 5.x branch to allow people the freedom to contribute to an older version

[thet]

I've two comments here. not sure, if they are relevant. will do a more in-depth review later today or first thing tomorrow.
Anyways, I'm running the Plone test suite now on it. If it breaks I'll try with using the pytz variant.

[thet]

Shouldn't this also mentioned for version 5?

[niccokunzmann]

Looking at these:

• Drop claim to support for Python below 3.7 #513
• Release with fixes to the 4.x branch #459

We do not really make a release for 4.x, nobody invests time. For 5.x there will not really be a future release either because you can add one line to the code and then use 6.x. So, the claims will be dropped to support older versions but this is not part of this PR. The PR is for zoneinfo compatibility, also not for the next release. We can create an issue for the next release and what should be done, I think.

[thet]

Plone test suite running with this branch here:
https://jenkins.plone.org/job/pull-request-6.1-3.10/204/
and
https://jenkins.plone.org/job/pull-request-6.1-3.12/452/

[thet]

Test run:
https://jenkins.plone.org/job/pull-request-6.1-3.10/
https://jenkins.plone.org/job/pull-request-6.1-3.12/

[niccokunzmann]

@thet, thanks for reviewing this! I am not able to make sense of the Plone Jenkins tests. What do you think about them?

If they test the main version of Plone, then they are missing this line:

icalendar.use_pytz()

to switch to the old behavior.

[thet]

Some requests. Other than that, LGTM!

[niccokunzmann]

I merged master.

Then, I edited the README file so that it is clear that

• we extend and switch the functionality
• one is only affected by parsing results
• one can use timezones of all types

[thet]

looks good to me!

[stevepiercy]

Just a few docs changes, and it's good to go.

[niccokunzmann]

@stevepiercy, thanks for the changes. I applied them to the PR. I will follow #630 and within this merge this as the reviews are positive! Thanks for the cooperation on the PR and the feedback to make it happen!