Most GNU/Linux distributions, Android, iOS, macOS and Microsoft Windows all have at least version 2025a of TZDB, so properly-updated installations should be working correctly after Paraguay's rule change yesterday. However, Repology reports[1] that the latest stable versions of the following GNU/Linux distributions are still based on TZDB 2024b and thus presumably are misbehaving in Paraguay: Apertis, nixpkgs, OpenWrt, Pardus, Rosa, Trisquel, Ubuntu Of these Ubuntu is best known, and it has several downstream distros that I assume are also affected. So Ubuntu may be the most important laggard for Paraguay. In the list above, I omitted distros like Adélie that use TZDB versions that predate 2024b. I assume these distros are not intended to be up-to-date, are no longer maintained, have distro-specific patches, or aren't tracked accurately by repology. Many other systems also may be out of date for Paraguay; see the first paragraph of the section "The tz database"[2] for a partial list. I haven't tried to track them all. [1]: https://repology.org/project/tzdata/versions [2]: https://data.iana.org/time-zones/tz-link.html#tzdb