# What this PR does
This older version of recurring_ical_events does not call the pytz
.normalize() function, which can cause some invalid datetime objects to
return when a DST swap happens. For example: Nov 3, 2024 9:00 AM CDT
instead of the correct 8:00 AM CST). By calling tz.normalize on the end
date and checking if the time zone information changed, we can detect
when DST starts/stops and adjust the end date accordingly.
| | DST stopping on November 3, 2024: | DST starting on March 9, 2024 |
|-|-----------------------------------------|-----------------------------------|
| Before |

|

| After |

|

|
## Which issue(s) this PR closes
Closes#5247
## Checklist
- [ ] Unit, integration, and e2e (if applicable) tests updated
- [ ] Documentation added (or `pr:no public docs` PR label added if not
required)
- [ ] Added the relevant release notes label (see labels prefixed w/
`release:`). These labels dictate how your PR will
show up in the autogenerated release notes.
---------
Co-authored-by: Matias Bordese <mbordese@gmail.com>
# What this PR does
Remove
[`apps.get_model`](https://docs.djangoproject.com/en/3.2/ref/applications/#django.apps.apps.get_model)
invocations and use inline `import` statements in places where models
are imported within functions/methods to avoid circular imports.
I believe `import` statements are more appropriate for most use cases as
they allow for better static code analysis & formatting, and solve the
issue of circular imports without being unnecessarily dynamic as
`apps.get_model`. With `import` statements, it's possible to:
- Jump to model definitions in most IDEs
- Automatically sort inline imports with `isort`
- Find import errors faster/easier (most IDEs highlight broken imports)
- Have more consistency across regular & inline imports when importing
models
This PR also adds a flake8 rule to ban imports of `django.apps.apps`, so
it's harder to use `apps.get_model` by mistake (it's possible to ignore
this rule by using `# noqa: I251`). The rule is not enforced on
directories with migration files, because `apps.get_model` is often used
to get a historical state of a model, which is useful when writing
migrations ([see this SO answer for more
details](https://stackoverflow.com/a/37769213)). So `apps.get_model` is
considered OK in migrations (even necessary in some cases).
## Checklist
- [x] Unit, integration, and e2e (if applicable) tests updated
- [x] Documentation added (or `pr:no public docs` PR label added if not
required)
- [x] `CHANGELOG.md` updated (or `pr:no changelog` PR label added if not
required)
# What this PR does
- Adds [`mypy` static type checking](https://mypy-lang.org/) to our CI
pipeline. Currently there is still a **ton** of errors being returned by
the tool, as we'll need to fix pre-existing errors. I think we can
slowly chip away at these errors in small PRs, doing them all in one
large PR is likely very risky.
- Also, this PR starts chipping away at one of the main type errors that
we have which is accessing the `datetime` class (from the `datetime`
library) or `timedelta` function on the `django.utils.timezone` module.
Basically we should be instead accessing these two objects from the
native `datetime` module. This makes sense because the [`__all__`
attribute](https://github.com/django/django/blob/main/django/utils/timezone.py#L14-L30)
in `django.utils.timezone` does not re-export `datetime` or `timedelta`.
- splits `engine` dependencies out into `requirements.txt` and
`requirements-dev.txt`
## Checklist
- [ ] Unit, integration, and e2e (if applicable) tests updated (N/A)
- [ ] Documentation added (or `pr:no public docs` PR label added if not
required) (N/A)
- [ ] `CHANGELOG.md` updated (or `pr:no changelog` PR label added if not
required) (N/A)