core: Can't save any new To Do items when system timezone is not valid timezone

The problem

Using Local To Do list integration. Created a new To Do list item, then I edited it to add a description; once I tried to save it (& I DID NOT specify a due date or time), I then received this error, which was also posted to syslog: “No timezone information available for event: {key}”. I could NOT save the To Do item & discovered that I could start new items, but could not edit them. But… I was able to edit items that had been previously created. Just can’t edit any new items.

What version of Home Assistant Core has the issue?

core-core-2024.3.0

What was the last working version of Home Assistant Core?

core-core-2024.2.5

What type of installation are you running?

Home Assistant Supervised

Integration causing the issue

Local To-do

Link to integration documentation on our website

https://www.home-assistant.io/integrations/local_todo

Diagnostics information

Attempted the above several times and kept getting the error. Checked my ‘timezone’ and it was correct: (GMT-06:00) Central Time. I attempted to enter a due date and time, but still got the error. I was not able to save the To Do item so this basically means I cannot create any new To Do list items. NOTE: I was able to successfully edit and modify existing To Do items. Just not create any new ones. I have two To Do lists & and I could not create new items in either list.

Example YAML snippet

No response

Anything in the logs that might be useful for us?

Logger: homeassistant.components.websocket_api.http.connection
Source: components/websocket_api/commands.py:239
integration: Home Assistant WebSocket API (documentation, issues)
First occurred: 1:40:31 PM (5 occurrences)
Last logged: 1:54:47 PM

[547421976384] No timezone information available for event: {key}
Traceback (most recent call last):
  File "/usr/local/lib/python3.12/site-packages/ical/store.py", line 64, in _ensure_timezone
    return Timezone.from_tzif(key)
           ^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/ical/timezone.py", line 166, in from_tzif
    info = timezoneinfo.read(key)
           ^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/ical/tzif/timezoneinfo.py", line 69, in read
    raise TimezoneInfoError(f"Unable to find timezone in system timezones: {key}")
ical.tzif.timezoneinfo.TimezoneInfoError: Unable to find timezone in system timezones: CST

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/components/websocket_api/commands.py", line 239, in handle_call_service
    response = await hass.services.async_call(
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/core.py", line 2319, in async_call
    response_data = await coro
                    ^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/core.py", line 2356, in _execute_service
    return await target(service_call)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/helpers/service.py", line 905, in entity_service_call
    single_response = await _handle_entity_call(
                      ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/helpers/service.py", line 975, in _handle_entity_call
    result = await task
             ^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/components/todo/__init__.py", line 511, in _async_update_todo_item
    await entity.async_update_todo_item(item=TodoItem(**updated_data))
  File "/usr/src/homeassistant/homeassistant/components/local_todo/todo.py", line 157, in async_update_todo_item
    TodoStore(self._calendar).edit(todo.uid, todo)
  File "/usr/local/lib/python3.12/site-packages/ical/store.py", line 319, in edit
    self._apply_edit(
  File "/usr/local/lib/python3.12/site-packages/ical/store.py", line 379, in _apply_edit
    self._ensure_timezone(new_item.dtstart)
  File "/usr/local/lib/python3.12/site-packages/ical/store.py", line 394, in _ensure_timezone
    if (new_timezone := _ensure_timezone(dtstart, self._timezones)) is not None:
                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/ical/store.py", line 66, in _ensure_timezone
    raise EventStoreError(
ical.exceptions.EventStoreError: No timezone information available for event: {key}

Additional information

I had forgotten to mention that I had also restarted HA and tested again. Same result.