US symlinks missing in /usr/share/zoneinfo -> now in tzdata-legacy

[Bill Evans]

On 22.04 Jammy with tzdata version 2024a-0ubuntu0.22.04 installed, we have `/usr/share/zoneinfo/US/*` symlinks. On 23.10 Mantic with tzdata version 2024a-0ubuntu0.23.10, we do not. Is this an intentional removal? I don't follow the IANA mailing lists, but I had thought/assumed that "Country/Region" symlinks were being maintained for backward compatibility.

Many tools I use reference multiple timezones (regardless of the system TZ), so it is necessary to have them available. As a temporary workaround, we can make the symlinks manually.

[Benjamin Drung (bdrung)]

Yes, this is an intentional change. All backward compatibility symlinks were moved to the tzdata-legacy package. Please install this package for such use cases.

[Bill Evans (r2evans)]

Thank you, that certainly resolves the missing files.

While I understand the reason behind the switch, I can't find where the "intentional change" is communicated. There is no `apt changelog tzdata`, and nothing else I see gives me a hint that the package was split in that way. While it may not impact everybody like it did me, is there some way to formally communicate this, perhaps within the package description for `tzdata`?

[Benjamin Drung (bdrung)]

In Ubuntu 24.04 (noble) we have /usr/share/doc/tzdata/NEWS.Debian.gz:

tzdata (2023d-1) unstable; urgency=medium

    From 2023c-8 on the tzdata package ships only timezones that follow the
    current rules of geographical region (continent or ocean) and city name.
    All legacy timezone symlinks (old or merged timezones mentioned in the
    upstream backward file) were moved to tzdata-legacy. This includes the
    US/* timezones.

    Please install tzdata-legacy in case you need the legacy timezones or to
    restore the previous behavior. This might be needed in case the system
    provides timezone-aware data over the network (e. g. SQL databases).

 -- Benjamin Drung <email address hidden> Tue, 02 Jan 2024 14:17:33 +0100

The debian changelog contains for 2023c-8:

  * Ship only timezones in tzdata that follow the current rules of geographical
    region (continent or ocean) and city name. Move all legacy timezone symlinks
    (that are upgraded during package update) to tzdata-legacy. This includes
    dropping the special handling for US/* timezones. (Closes: #1040997)

Improvements to the documentation are welcome.

[Bill Evans (r2evans)]

I see it now within `/usr/share/doc/tzdata/changelog.Debian.gz`, that's a file I did not check. Thank you!