Alas, that last line applies to times after time zone rules have been exhausted; if differing rules extend in to the future, the zones may not be the same at present.

    @dashdashado

On Mon, Nov 3, 2025, 1:23 PM Paul Gilmartin via tz <tz@iana.org> wrote:
On 11/2/25 03:11, Guillermo Rodriguez Garcia via tz wrote:
>     ...
>
> So, the question: Any suggestions on how to filter timezones within
> each country to drop those that as of today are not relevant except
> for historical differences?
>     ...
The last line of each timezone definition appears to contain the current
POSIX definition.  (I don't know where this is documented.)
If those lines are identical, might zones be merged?

--
gil