Brasília is 4 hours behind Barcelona
Best overlap: 12:00 PM to 6:00 PM in Barcelona is 8:00 AM to 2:00 PM in Brasília.
Barcelona and Brasília overlap from 12:00 PM to 6:00 PM (Barcelona) to the equivalent 8:00 AM to 2:00 PM in Brasília — that's your meeting window. A 6-hour overlap gives you real choice here — early or late in the window both work comfortably. One seasonal catch: Barcelona springs forward and falls back, but Brasília doesn't, so the gap changes by an hour for several months of the year.