[tz] Moving more zones to 'backzone'

Peter Krefting peter at softwolves.pp.se
Wed Aug 17 06:28:30 UTC 2022

On Fri, 12 Aug 2022, Paul Eggert via tz wrote:

>> The zone1970.tab files provides me with a list of time zones, one per 
>> country
> Not sure about the "one per country" part. Some countries have more than one 
> Zone, and some Zones have more than one country.

Indeed, a bit poor wording from my side. A vast majority of countries have
only one zone, so basing it on country is not such a bad idea.

I'm sorry if some of this comes off as a rant, it isn't, it is just me
trying to present the data thas is made available to me in a manner that is
useful for the end-user of our product, without introducing a lot of extra
stuff that I have to maintain myself.

My thinking is to display the country names as the top selection entry, as
most people know the country they live in, and for the vast majority that is
enough (special care has to be taken for the multi-zone countries). I do not
do this today.

I currently have a simple drop-down selector where I group zones based on
the current clock time in the zone (so the list will be ordered differently
depending when in the year it is opened), and as the selectable entry I
currently have "city" (the BBB part of the AAA/BBB or AAA/CCC/BBB zone
specifiers), time zone abbreviation (if any) and the comment. This goes a
long way to make it usable, but using the city name isn't the best solution,
as many on the list have already noted.

Showing "Norway (CEST)" instead of "Oslo (CEST)" would probably be an
improvement. Showing "Germany, Denmark, Norway, Sweden, Svalbard (CEST)"
probably not as much.

> This sort of issue is not new to 2022b. For example, if software ignores 
> zone1970.tab's column 1 it's not immediately obvious that Europe/Prague 
> covers at least part of Slovakia, and this has been true ever since 
> zone1970.tab was introduced in release 2014f.

I was looking for that, but the change predated the zone1970.tab file
itself, so I didn't find where to deduplicate that, I need to do some
further research on that.

We recently released what is likely to be the last patch of the oldest
version that have proper time zone support (it supports side-loading
timezone updates), so I can only play with the zone1970.tab file to make
the list easier to read for those existing systems.

\\// Peter - http://www.softwolves.pp.se/

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