[Dateutil] TZDB questions

[Shrayas rajagopal]

Hi folks,

I am working on a talk for PyCon India 2023 where I aim to introduce
developers to the concepts of timestamps and time zones along with
providing some practical suggestions (based on my experience) on how
to handle timestamps and future dates in the context of applications.

To provide some context, originally I am from the .NET world, where a
library like NodaTime exists, which keeps itself updated with the
tzdata whenever there is a release made by IANA.

I remember watching multiple talks which reference that each release
of dateutil carries the tzdb update as well. But when I look at the
tzinfo in the current release, I see that the version is 2021a [0]. So
I am a bit confused.

I also recall watching Paul talking about this and saying that
dateutil relies more on the tzdata from the underlying operating
system and uses the embedded tzinfo only in platforms like Windows.

I am a bit confused by the TZDB handling here. In particular here are
my questions:

1. When is the TZDB shipped with dateutil updated?
2. If someone has stopped unattended updates on their distro, how do
you rely on the underlying tzdata from the distribution?
3. Is there any way to find out the TZDB version that dateutil is
using to provide us with the timezone & offset information?

Would really appreciate any information that y'all can provide on the same?

Cheers and thanks for putting the time in for writing such a great library.

Regards,
Shrayas

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Footnotes
[0]: https://github.com/dateutil/dateutil/blob/master/zonefile_metadata.json