Barcelona is 1 hour behind Istanbul
Best overlap: 9:00 AM to 6:00 PM in Istanbul is 8:00 AM to 5:00 PM in Barcelona.
Target 9:00 AM to 6:00 PM in Istanbul, which lands at 8:00 AM to 5:00 PM for the Barcelona side. Barcelona is 1 hour behind Istanbul, but with 9 hours of common ground you can hold morning or afternoon meetings without anyone working odd hours. Don't be caught out by clock changes — Barcelona observes daylight saving and Istanbul doesn't, so the offset varies by an hour through the year.