Hi, I notice a little nuance that would be nice be corrected, between 1963-10-23 and 1963-12-9 in brazil only Minas Gerais , Espirito Santo, Rio de Janeiro and Sao Paulo had sumer time. this can be verified in the links. http://pcdsh01.on.br/DecHV.html http://pcdsh01.on.br/HV52700.htm http://pcdsh01.on.br/HV53071.htm I propose separate Zone America/Sao_Paulo in one more zone America/Brasilia, the configuration would be like: # Minas Gerais (MG), Espirito Santo (ES), # Rio de Janeiro (RJ), Sao Paulo (SP) Zone America/Sao_Paulo -3:06:28 - LMT 1914 -3:00 Brazil BR%sT 1963 Oct 23 00:00 -3:00 1:00 BRST 1964 -3:00 Brazil BR%sT # Goias (GO), Distrito Federal (DF), Parana (PR), # Santa Catarina (SC), Rio Grande do Sul (RS) Zone America/Brasilia -3:06:28 - LMT 1914 -3:00 Brazil BR%sT 1963 Dec 9 00:00 -3:00 1:00 BRST 1964 -3:00 Brazil BR%sT Ps.:Sorry my poor english