There is a bug in the DST setting for Brasilia. Right now, it says:
DST starts 3 month 2nd Sunday 2 hours
DST ends 10 month 2 Sunday 2 hours
The correct is:
DST starts 10 month 3rd Sunday 0 hours
DST ends 2 month 3rd Sunday 0 hours
From Wikipedia:
DST starts at 00:00 on the third Sunday...