I'm forwarding this message from Katia, who is not on the time zone mailing list. Those of you who are on the list, please direct replies appropriately. --ado From: Katia [mailto:katia@astrologiainlinea.it] Sent: Wednesday, September 22, 2010 6:31 To: tz@lecserver.nci.nih.gov Subject: Time Zone in Paris Hello, we use your database to make astrological calculations. With regard to the time zone of Paris from 1945 to 1976 it results a strange data that conflicts over other resources credited as Shank, according to your database in 1971 the Time zone Paris was 0. Can you confirm this and show me the source? Thanks and good job Katia
Katia wrote:
With regard to the time zone of Paris from 1945 to 1976 it results a strange data that conflicts over other resources credited as Shank, according to your database in 1971 the Time zone Paris was 0.
Sorry, I don't see that problem. According to the tz database, the time zone in Paris was one hour ahead of UTC during that period. This agrees with Shanks & Pottenger 2003 (ISBN 0-035127-88-7); I just now checked my printed copy. It also agrees with the Ephemerides Astronomiques for 1998 from Bureau des Longitudes, according to email that we received on 1997-12-12 from Denis Excoffier. These two sources disagree only about exactly when this long period of UTC+1 ended. Shanks & Pottenger say that it ended on 1976-03-28 at 02:00 local time, whereas Excoffier wrote that it ended at 00:00 UTC, i.e., at 01:00 local time. Currently the tz database agrees with Excoffier, but we always welcome any more-authoritative sources, such as reliable newspapers published at the time.
----- Original Message ----- From: "Paul Eggert" <eggert@cs.ucla.edu> To: <katia@astrologiainlinea.it> Cc: <tz@lecserver.nci.nih.gov> Sent: Thursday, September 23, 2010 6:36 AM Subject: Re: FW: Time Zone in Paris
Katia wrote:
With regard to the time zone of Paris from 1945 to 1976 it results a strange data that conflicts over other resources credited as Shank, according to your database in 1971 the Time zone Paris was 0.
Sorry, I don't see that problem. According to the tz database, the time zone in Paris was one hour ahead of UTC during that period. This agrees with Shanks & Pottenger 2003 (ISBN 0-035127-88-7); I just now checked my printed copy. It also agrees with the Ephemerides Astronomiques for 1998 from Bureau des Longitudes, according to email that we received on 1997-12-12 from Denis Excoffier. These two sources disagree only about exactly when this long period of UTC+1 ended. Shanks & Pottenger say that it ended on 1976-03-28 at 02:00 local time, whereas Excoffier wrote that it ended at 00:00 UTC, i.e., at 01:00 local time. Currently the tz database agrees with Excoffier, but we always welcome any more-authoritative sources, such as reliable newspapers published at the time.
I didn't find a newpaper source archive from 1975 on the net. Here is the legal text that define the 1976 time shift : http://www.legifrance.gouv.fr/jopdf/common/jo_pdf.jsp?numJO=0&dateJO=1975092... Text say Excoffier is right, time has been shifted 1 hour in advance at 0 hour UTC the 28 march 1976. The return was the 25 september 1976 at 23 hour UTC (so the 26 at 1h in local time).. On 1977, shift has been made at a different UTC time. http://www.legifrance.gouv.fr/jopdf/common/jo_pdf.jsp?numJO=0&dateJO=1976092... Summer shift was the 3 april 1977 at 2 hour UTC, time was shifted again 1 hour in advance. The return was the 25 september 1977 at 1 hour UTC You should be able to find any related change looking for 'heure legale' in http://www.legifrance.gouv.fr/initRechTexte.do Gilles
Thank you for your reply and for having put my question in the mailing lists to which I will enjoy soon. The problem is that according to the downloaded version of the database on the Google site for updates http://code.google.com/p/tzdata/ in 1971 the time zone in Paris wasn't one hour ahead of UTC. Here is part of Paris file in XML version <from>1945-04-02T01:00:00Z</from> <to>1945-09-16T01:00:00Z</to> <dst>true</dst> <offset>7200</offset> <name>WEMT</name> </period> - <period> <from>1945-09-16T01:00:00Z</from> <to>1976-03-28T01:00:00Z</to> <dst>false</dst> <offset>0</offset> <name>WET</name> </period> - <period> Is that file correct ? Katia -----Messaggio originale----- Da: Paul Eggert [mailto:eggert@cs.ucla.edu] Inviato: giovedì 23 settembre 2010 06:37 A: katia@astrologiainlinea.it Cc: tz@elsie.nci.nih.gov Oggetto: Re: FW: Time Zone in Paris Katia wrote:
With regard to the time zone of Paris from 1945 to 1976 it results a strange data that conflicts over other resources credited as Shank, according to your database in 1971 the Time zone Paris was 0.
Sorry, I don't see that problem. According to the tz database, the time zone in Paris was one hour ahead of UTC during that period. This agrees with Shanks & Pottenger 2003 (ISBN 0-035127-88-7); I just now checked my printed copy. It also agrees with the Ephemerides Astronomiques for 1998 from Bureau des Longitudes, according to email that we received on 1997-12-12 from Denis Excoffier. These two sources disagree only about exactly when this long period of UTC+1 ended. Shanks & Pottenger say that it ended on 1976-03-28 at 02:00 local time, whereas Excoffier wrote that it ended at 00:00 UTC, i.e., at 01:00 local time. Currently the tz database agrees with Excoffier, but we always welcome any more-authoritative sources, such as reliable newspapers published at the time.
participants (4)
-
Gilles Espinasse -
Katia -
Olson, Arthur David (NIH/NCI) [E] -
Paul Eggert