Brasília is 4 hours behind Frankfurt
Best overlap: 12:00 PM to 6:00 PM in Frankfurt is 8:00 AM to 2:00 PM in Brasília.
Your shared working hours run 12:00 PM to 6:00 PM in Frankfurt (8:00 AM to 2:00 PM in Brasília). With 6 hours in common, treat scheduling almost as if the two cities were in the same region. The window above shifts seasonally: Frankfurt keeps daylight saving while Brasília ignores it.