Brasília is 5 hours behind Bucharest
Best overlap: 1:00 PM to 6:00 PM in Bucharest is 8:00 AM to 1:00 PM in Brasília.
1:00 PM to 6:00 PM in Bucharest is when Brasília is also working, at 8:00 AM to 1:00 PM their time. Roughly 5 hours of common time means scheduling is manageable; just avoid the very edges of the window. Heads up: because Bucharest changes its clocks and Brasília doesn't, the difference moves by an hour twice a year. Confirm the overlap around the DST switch.