[tz] Suggestion for addition of America/Brasilia entry to time zone database

[Gabriel Gaspar via tz]

Hello there, and sorry for the intrusion.

I presently write to this list with a suggestion for addition of an entry in the time zone
database, America/Brasilia, or at least for a clarification on why there may not be one.
Being the standard official time in Brazil, I firmly believe there should be one such
entry (unless, of course, matters of greater power disallow it).

The official time used in Brazil is called "the Brasilia official time" (UTC -3:00),
Brasilia being the capital of Brazil. Note that the official country name is Brasil,
with an 's', and the official capital name is Brasília, with an acute on the first 'i'.
I am writing the country name with 'z' and leaving the aforementioned acute out
for internationalization purposes. Inside Brazilian territory, the remainder time zones
are usually referred and adjusted having Brasilia time as a referential base, e.g.
"Brasilia time +1", "Brasilia time -1" etc. Even more, event times in Brazil (games, DST
start/end, official announcements) are all informed, be it via government official
channels or mass media, in Brasilia's official time, further evidencing the importance
of Brasilia as a reference for setting times inside country territory.

That being said, I have always wondered why it is that Brasilia is not listed as one
of the time zones in the data base for South America. It is the official time for Brazil
and the name does not clash with any other name in the database (America/Brasilia).
Instead, it is relegated to an indirect mention, (Brasilia is located inside Distrito Federal
(DF)), in a comment for the time zone America/Sao_Paulo. São Paulo is a major city in
Brazil, but by no means the capital itself, nor does it retain any authoritative power in
setting or representing the official time, which Brasilia does. Actually, the
America/Sao_Paulo time zone entry seems to be doing what an America/Brasilia
time zone entry should be doing.

Thus, my suggestion would be either for the addition of something such as
America/Brasilia to the time zone database, or for the renaming of
America/Sao_Paulo to America/Brasilia in order to more accurately represent what that
time zone entry stands for. The former suggestion would add more information to the
database, but other than occupying more space I fail to see further problems with that
addition. The latter suggestion could break some scripts that rely on the time zone
name for correct operation, although I currently have no knowledge of one such script nor
how crucial its operation could be.

Without further ado, I thank you for the time to read this, and appreciate the time for
such considerations.

Regards,
Gabriel G. Gaspar

[Paul Eggert]

Post by Gabriel Gaspar via tz
I have always wondered why it is that Brasilia is not listed as one
of the time zones in the data base for South America.

This is covered in the Theory file, which says, "Use the most populous among
locations in a zone, e.g. prefer 'Shanghai' to 'Beijing'. Among locations with
similar populations, pick the best-known location, e.g. prefer 'Rome' to 'Milan'."

In this respect Brazil is treated like other countries. In China, for example,
although standard time is popularly called "北京时间" ("Beijing time"), the
corresponding Zone name is Asia/Shanghai because Shanghai is the largest city in
the region.

The intent is that Zone names be English-language city labels rather than
localized time zone names. For the latter, please see the CLDR project
<http://cldr.unicode.org/>.

[Random832]

Post by Gabriel Gaspar via tz
Hello there, and sorry for the intrusion.
I presently write to this list with a suggestion for addition of an
entry in the time zone database, America/Brasilia, or at least for a
clarification on why there may not be one. Being the standard official
time in Brazil, I firmly believe there should be one such entry
(unless, of course, matters of greater power disallow it).

This is essentially the same as the Beijing/Shanghai problem that has
been discussed before - the policy is that the timezone name in the
timezone database is based on the largest city that the timezone applies
to, regardless of the existence of another city which may be part of a
popular or official name of the same time zone. Thus China's timezone is
"Asia/Shanghai" despite being called "Beijing Time".

This is considered acceptable because the raw timezone name is not
supposed to be displayed to users; the string meant to be displayed to
users is the description in zone.tab, which is "Brazil (southeast: GO,
DF, MG, ES, RJ, SP, PR, SC, RS)" for America/Sao_Paulo. For its part,
Asia/Shanghai's description is "east China - Beijing, Guangdong,
Shanghai, etc." Perhaps Asia/Sao_Paulo should likewise be "southeast
Brazil - Brasília, Rio de Janeiro, São Paulo, etc." and leave the
precise enumeration of states to the shapefile project.

It's also worth noting that timezones in the timezone database don't
generally correspond one-to-one with civil timezones, but subdivide them
based on regions within a timezone that used to be in a different civil
timezone before the present day but after 1970, or have or had different
rules for daylight saving time. For example, Mato Grosso and Mato Grosso
do Sol have different timezones (America/Cuiaba and
America/Campo_Grande, respectively), because the former did not observe
daylight saving time in 2003-2004. In all, there are sixteen timezones
applying to various parts of Brazil, and it's simply good fortune that
there is (so far as I can tell) only one that applies to the whole
section of UTC-3:00 that presently observes daylight saving time.

Out of curiosity, are the northern parts of UTC-3:00 that do not observe
daylight saving time (Bahia, Fortaleza, etc) also considered "Brasilia
Time"? Or for only part of the year, and the rest it is "Brasilia time
-1", when they're not the ones whose clocks have changed [and then
presumably Fernando de Noronha, whose clocks also do not change, is
"Brasilia time" for part of the year]? How should this be differentiated
if this name is used?