zdump -v America/Sao_Paulo |grep 200[78]
America/Sao_Paulo  Sun Feb 25 01:59:59 2007 UTC = Sat Feb 24 23:59:59 2007 BRST isdst=1 gmtoff=-7200
America/Sao_Paulo  Sun Feb 25 02:00:00 2007 UTC = Sat Feb 24 23:00:00 2007 BRT isdst=0 gmtoff=-10800
America/Sao_Paulo  Sun Nov  4 02:59:59 2007 UTC = Sat Nov  3 23:59:59 2007 BRT isdst=0 gmtoff=-10800
America/Sao_Paulo  Sun Nov  4 03:00:00 2007 UTC = Sun Nov  4 01:00:00 2007 BRST isdst=1 gmtoff=-7200
America/Sao_Paulo  Sun Feb 24 01:59:59 2008 UTC = Sat Feb 23 23:59:59 2008 BRST isdst=1 gmtoff=-7200
America/Sao_Paulo  Sun Feb 24 02:00:00 2008 UTC = Sat Feb 23 23:00:00 2008 BRT isdst=0 gmtoff=-10800
America/Sao_Paulo  Sun Nov  2 02:59:59 2008 UTC = Sat Nov  1 23:59:59 2008 BRT isdst=0 gmtoff=-10800
America/Sao_Paulo  Sun Nov  2 03:00:00 2008 UTC = Sun Nov  2 01:00:00 2008 BRST isdst=1 gmtoff=-7200