[Boost-bugs] [Boost C++ Libraries] #7268: Invalid DST for Europe/Paris before 1996 (using tzdatabase)

Subject: [Boost-bugs] [Boost C++ Libraries] #7268: Invalid DST for Europe/Paris before 1996 (using tzdatabase)
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2012-08-23 09:34:24

#7268: Invalid DST for Europe/Paris before 1996 (using tzdatabase)
-------------------------------------------+--------------------------------
 Reporter:  guillaume.v.sanchez@…          |       Owner:  az_sw_dude
     Type:  Bugs                           |      Status:  new       
Milestone:  To Be Determined               |   Component:  date_time 
  Version:  Boost 1.52.0                   |    Severity:  Problem   
 Keywords:  europe dst date time           |  
-------------------------------------------+--------------------------------
 Hello,

 Let me start with an example :
 For 1992, boost::datetime gives me (using the given timezone database) DST
 period from
 1992-Mar-29 02:00:00 TO 1992-Oct-25 03:00:00

 That's simply wrong. For 1996 and following years, it's correct, simply
 because, in 1996, France decided that DST occurs in the end of October.
 Before that date, it occured in the end of September.

 Here is a table of true DST dates (dates are in European form,
 "day/month") :


 {{{
 1976 : 28/3 -- 26/9
 1977 : 3/4 -- 5/9
 1978 : 2/4 -- 1/10
 1979 : 1/4 -- 30/9

 1980 : 6/4 -- 28/9
 1981 : 29/3 -- 27/9
 1982 : 28/3 -- 26/9
 1983 : 27/3 -- 25/9
 1984 : 25/3 -- 30/9
 1985 : 31/3 -- 29/9
 1986 : 30/3 -- 28/9
 1987 : 29/3 -- 27/9
 1988 : 27/3 -- 25/9
 1989 : 26/3 -- 24/9

 1990 : 25/3 -- 30/9
 1991 : 31/3 -- 29/9
 1992 : 29/3 -- 27/9
 1993 : 28/3 -- 26/9
 1994 : 27/3 -- 25/9
 1995 : 26/3 -- 24/9

 ================

 1996 : 31/3 -- 27/10
 1997 : 30/3 -- 26/10
 1998 : 29/3 -- 25/10
 1999 : 28/3 -- 31/10

 2000 : 26/3 -- 29/10
 2001 : 25/3 -- 28/10
 2002 : 31/3 -- 27/10
 2003 : 30/3 -- 26/10
 2004 : 28/3 -- 31/10
 2005 : 27/3 -- 30/10
 2006 : 26/3 -- 29/10
 2007 : 25/3 -- 28/10
 2008 : 30/3 -- 26/10
 2009 : 29/3 -- 25/10

 2010 : 28/3 -- 24/10
 2011 : 27/3 -- 30/10
 }}}

 Thank you,
 Guillaume

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/7268>
Boost C++ Libraries <http://www.boost.org/>
Boost provides free peer-reviewed portable C++ source libraries.