How can I add a new time zone: 'America/Joao Pessoa'?
Hi all! How can I add a new time zone? I'd like add 'America/Joao Pessoa'. Joao Pessoa[1] is the capital of Paraiba state, in Brazil. [1] https://en.wikipedia.org/wiki/Jo%C3%A3o_Pessoa,_Para%C3%ADba Best Regards, -- --fx
On Jan 31, 2021, at 2:13 PM, Fabrício Cabral <fabriciofx@gmail.com> wrote:
How can I add a new time zone? I'd like add 'America/Joao Pessoa'. Joao Pessoa[1] is the capital of Paraiba state, in Brazil.
The first step would be to give the history of time zone changes in the region that contains it, indicating how its history differs from that of other tzdb regions in Brazil (America/Noronha, America/Belem, America/Santarem, America/Fortaleza, America/Recife, America/Araguaina, America/Maceio, America/Bahia, America/Sao_Paulo, America/Campo_Grande, America/Cuiaba, America/Porto_Velho, America/Boa_Vista, America/Manaus, America/Eirunepe, and America/Rio_Branco), so that it requires a new region.
Hi Guy! The time zone changes are the same of America/Fortaleza, but nobody uses it as to configure time zone to João Pessoa because America/Fortaleza is further than America/Recife. So, by logic, Joao Pessoa people choose America/Recife instead of America/Fortaleza. Best Regards. On Sun, Jan 31, 2021 at 7:30 PM Guy Harris <gharris@sonic.net> wrote:
On Jan 31, 2021, at 2:13 PM, Fabrício Cabral <fabriciofx@gmail.com> wrote:
How can I add a new time zone? I'd like add 'America/Joao Pessoa'. Joao Pessoa[1] is the capital of Paraiba state, in Brazil.
The first step would be to give the history of time zone changes in the region that contains it, indicating how its history differs from that of other tzdb regions in Brazil (America/Noronha, America/Belem, America/Santarem, America/Fortaleza, America/Recife, America/Araguaina, America/Maceio, America/Bahia, America/Sao_Paulo, America/Campo_Grande, America/Cuiaba, America/Porto_Velho, America/Boa_Vista, America/Manaus, America/Eirunepe, and America/Rio_Branco), so that it requires a new region.
-- --fx
Fabrício, On Sun, 31 Jan 2021 at 17:40, Fabrício Cabral <fabriciofx@gmail.com> wrote:
America/Fortaleza is further than America/Recife. So, by logic, Joao Pessoa people choose America/Recife instead of America/Fortaleza.
For recent and current timestamps, there is no difference between America/Fortaleza and America/Recife. Both of those entries have used UTC-03 year-round since October 2002. The only modern timestamps for which these two entries differ is over one week in the October 2000, when Pernambuco appears to have ended Daylight Saving Time after one week while Paraíba and other neighboring states ended it after two weeks. This difference is shown in lines 983–1000 of the 'southamerica' file in version 2021a. https://github.com/eggert/tz/blob/2021a/southamerica#L983-L1000 # Maranhão (MA), Piauí (PI), Ceará (CE), Rio Grande do Norte (RN), # Paraíba (PB) Zone America/Fortaleza -2:34:00 - LMT 1914 -3:00 Brazil -03/-02 1990 Sep 17 -3:00 - -03 1999 Sep 30 -3:00 Brazil -03/-02 2000 Oct 22 -3:00 - -03 2001 Sep 13 -3:00 Brazil -03/-02 2002 Oct 1 -3:00 - -03 # # Pernambuco (PE) (except Atlantic islands) Zone America/Recife -2:19:36 - LMT 1914 -3:00 Brazil -03/-02 1990 Sep 17 -3:00 - -03 1999 Sep 30 -3:00 Brazil -03/-02 2000 Oct 15 -3:00 - -03 2001 Sep 13 -3:00 Brazil -03/-02 2002 Oct 1 -3:00 - -03 This difference of one hour for one week in 2000 is the reason that America/Fortaleza and America/Recife are separate entries in our database, so technically America/Fortaleza is more correct to use for João Pessoa, but there is otherwise no difference since 1914. Please see our project's guidelines for creating new timezone identifier entries: https://ftp.iana.org/tz/theory.html#naming In particular, among our goals are to "[u]niquely identify every timezone where clocks have agreed since 1970", which means that "[i]f all the clocks in a timezone have agreed since 1970, [we] do not bother to include more than one timezone". Notably, a city being large or being a capital of a region or country is not sufficient for us to add a new entry. The United States, for example, is mostly covered by a small handful of entries, and many US states do not have separate entries of their own as they have always matched neighboring states since 1970. The time zone changes are the same of America/Fortaleza The listing above shows that our records agree that clocks in João Pessoa and the state of Paraíba have matched clocks in Fortaleza, the state of Ceará, and several other neighboring areas since 1914, which is well before our 1970 cutoff. If that information is incorrect, we'd be happy to hear of reliable references to support a proposed change. But otherwise, we're unlikely to add a separate America/Joao_Pessoa entry. -- Tim Parenti
On Jan 31, 2021, at 2:39 PM, Fabrício Cabral <fabriciofx@gmail.com> wrote:
The time zone changes are the same of America/Fortaleza,
So there shouldn't be a new zone, as they're the same.
but nobody uses it as to configure time zone to João Pessoa because America/Fortaleza is further than America/Recife. So, by logic, Joao Pessoa people choose America/Recife instead of America/Fortaleza.
People shouldn't be asked to make that choice in the first place - people shouldn't even know what "America/Fortaleza" or "America/Recife" (or America/Los_Angeles or Europe/Berlin or Asia/Shanghai or...) *are*, unless they're working on the tzdb or on time zone selection software! They should be, for example, asked to choose a city from a list of nearby cities, in which case one of the choices would be João Pessoa, in which case the current time zone would be set to See, for example, the time zone selection mechanism in macOS (where it works in that fashion, although you have to pick a region on the map first), or the mechanism in newer versions of Ubuntu.
On 2021-01-31 15:39, Fabrício Cabral wrote:
On Sun, Jan 31, 2021 at 7:30 PM Guy Harris wrote:
On Jan 31, 2021, at 2:13 PM, Fabrício Cabral wrote:
How can I add a new time zone? I'd like add 'America/Joao Pessoa'. Joao Pessoa[1] is the capital of Paraiba state, in Brazil.
The first step would be to give the history of time zone changes in the region that contains it, indicating how its history differs from that of other tzdb regions in Brazil (America/Noronha, America/Belem, America/Santarem, America/Fortaleza, America/Recife, America/Araguaina, America/Maceio, America/Bahia, America/Sao_Paulo, America/Campo_Grande, America/Cuiaba, America/Porto_Velho, America/Boa_Vista, America/Manaus, America/Eirunepe, and America/Rio_Branco), so that it requires a new region.
The time zone changes are the same of America/Fortaleza, but nobody uses it as to configure time zone to João Pessoa because America/Fortaleza is further than America/Recife. So, by logic, Joao Pessoa people choose America/Recife instead of America/Fortaleza. It appears to make little difference nowadays as those zones appear to have the same history except for a week in 2000; from southamerica:
... # Decree 3,630 <http://pcdsh01.on.br/Dec3630.jpg> (2000-10-13) # repeals DST in PE and RR, effective 2000-10-15 00:00. # Decree 3,632 <http://pcdsh01.on.br/Dec3632.jpg> (2000-10-17) # repeals DST in SE, AL, PB, RN, CE, PI and MA, effective 2000-10-22 00:00. ... Rule Brazil 2000 2001 - Oct Sun>=8 0:00 1:00 - ... # # Maranhão (MA), Piauí (PI), Ceará (CE), Rio Grande do Norte (RN), # Paraíba (PB) Zone America/Fortaleza -2:34:00 - LMT 1914 -3:00 Brazil -03/-02 1990 Sep 17 -3:00 - -03 1999 Sep 30 -3:00 Brazil -03/-02 2000 Oct 22 -3:00 - -03 2001 Sep 13 -3:00 Brazil -03/-02 2002 Oct 1 -3:00 - -03 # # Pernambuco (PE) (except Atlantic islands) Zone America/Recife -2:19:36 - LMT 1914 -3:00 Brazil -03/-02 1990 Sep 17 -3:00 - -03 1999 Sep 30 -3:00 Brazil -03/-02 2000 Oct 15 -3:00 - -03 2001 Sep 13 -3:00 Brazil -03/-02 2002 Oct 1 -3:00 - -03 ... -- Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada This email may be disturbing to some readers as it contains too much technical detail. Reader discretion is advised. [Data in binary units and prefixes, physical quantities in SI.]
participants (4)
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Brian Inglis -
Fabrício Cabral -
Guy Harris -
Tim Parenti