[tz] Dropping coordinates from zone1970.tab?

Aurelien Jarno aurelien at aurel32.net
Thu Sep 30 08:57:06 UTC 2021

On 2021-09-30 01:28, Guy Harris wrote:
> On Sep 30, 2021, at 12:51 AM, Aurelien Jarno via tz <tz at iana.org> wrote:
> > The point is not about choosing a timezone from a location, but rather
> > being able to show the cities linked to the timezones on a map so that
> > end users can pickup their timezone visually.
> "Cities linked to the timezones" as in "the cities whose names appear in the tzids of the regions", or as in "cities located within the regions"?
> The latter sounds far more useful to users than the former, as that way the end user can look for the city nearest to them, *even if that city doesn't happen to be the one used in the tzid for their region*.  It would also let them type in the name of a city near them to specify the region they're in (as long as the city isn't both near them *and* in a different zone.)

I am talking about the "the cities whose names appear in the tzids of
the regions", independently if they appear as tzid or as a link.

> > While timezones concept
> > might sometimes be difficult to end users, they are usually aware if a
> > city near to their location "has the same time or not".
> "Has the same time" as what?  Presumably not the city whose name appears in the tzid of the region, as users shouldn't have to be aware of tzids.

I am putting myself in the end user perspective. They do not know a lot
about timezones, however they usually know if the nearby cities from
their country follow the same rules regarding the time as the place they

> > Note that all the information for providing nice ways to select a
> > timezone for end-users is available in zone.tab,
> zone.tab has the boundaries of tzdb regions as well as the names of sufficiently significant cities in each region?  I don't see the names of the two largest cities near me in that file, much less the name of the smaller city in which I live, so I don't see any way to construct a nice way to select a timezone from that data.

Again you do not need the boundaries. Do you see the country where you
live in that file, and at least one city? Unless you live in Bouvet
Island or Heard Island and McDonald Islands, two uninhabited regions,
that should be the case. This means that you can be presented with a map
with cities to pick-up. Yes you need some clue to pick-up the right one,
but far less than when you have to pick-up Toronto when living in

Aurelien Jarno                          GPG: 4096R/1DDD8C9B
aurelien at aurel32.net                 http://www.aurel32.net

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