Invalid DST for Europe/Paris before 1996 (using tzdatabase)

[guillaume.v.sanchez@…]

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