[tz] Timezone in Brazil

[Guy Harris]

On Oct 9, 2015, at 1:05 PM, MARCIO IKEDA <marcio.ikeda at lge.com> wrote:

> It is strange that in Brazil we have 4 major timezone areas:

The US and Canada each have more than that, so there's nothing strange about that.  Russia has several time zones as well.

> People in Brazil, call it as “Horario de Brasilia”  as the main timezone.
> 
> In Windows it displays Brasilia for user.s

*Only* Brasilia?  There are several other cities in that time zone....

> In iOS has the Brasilia entry as well.

In iOS 9 on our iPad Air, in the "Time Zone" page for "Date & Time", you can type a number of different cities, including Brasilia, São Paulo, Rio de Janeiro, etc., and it will show the time zone by giving the city name you entered, rather than as "Horario de Brasilia" or "Brasilia Standard Time".  Perhaps it displays the name of the time zone somewhere else.

> In Android (my interested area) the timezone list uses Exemplar location, so “Sao Paulo” is shown.

If by "Exemplar location" you mean "the city whose name is used in the tzid", and that city is what they're displaying in the user interface as an indication of what time zone you're in, then that's incorrect behavior on Android's part.

> I don`t know how other systems manages timezones.

OS X has, in an English locale, "Brasilia Standard Time", which includes Brasilia, Sao Paolo, Rio de Janeiro, etc..

> But it is sure that there is some mismatching.

Yes, Android is broken, and, apparently, doesn't make full use of the CLDR (or perhaps makes *no* use of the CLDR).  It should be fixed to do more than just show the city from the tzid.

> What do you guys think ?
> 
> An entry like America/Brasilia, mapping to America/Sao_Paulo and changing displayName would be the solution ?

No, a fix to Android not to treat the tzid as something to be shown in the UI would be the solution.

Windows doesn't use the tzdb, but iOS does, and it manages to use the tzdb *and* still show the main Brazilian time zone as (Horário de) Brasilia, so it *is* possible to do the right thing without adding an alias for America/Sao_Paolo.

There is no "displayName" in the tzdb; that's a CLDR feature - and I don't see any displayName associated with zones or metazones.  I see

			<metazone type="Brasilia">
				<long>
					<generic>Horário de Brasília</generic>
					<standard>Horário Padrão de Brasília</standard>
					<daylight>Horário de Verão de Brasília</daylight>
				</long>
				<short>
					<generic>BRT</generic>
					<standard>BRT</standard>
					<daylight>BRST</daylight>
				</short>
			</metazone>

in the pt.xml file, but that's OK as it is.