Barcelona is 5 hours ahead of Montevideo
Best overlap: 8:00 AM to 1:00 PM in Montevideo is 1:00 PM to 6:00 PM in Barcelona.
Keep meetings inside 8:00 AM to 1:00 PM in Montevideo — that maps to 1:00 PM to 6:00 PM in Barcelona. With 5 hours of overlap, 8:00 AM in Montevideo (1:00 PM in Barcelona) is a comfortable, repeatable slot for both sides. These times hold for most of the year, but Barcelona's daylight saving (which Montevideo doesn't use) shifts them by an hour twice annually.