Beijing is 6 hours ahead of Barcelona
Best overlap: 8:00 AM to 12:00 PM in Barcelona is 2:00 PM to 6:00 PM in Beijing.
Aim for 8:00 AM to 12:00 PM Barcelona time — that's 2:00 PM to 6:00 PM over in Beijing. Around 4 hours of overlap is enough to work comfortably, as long as meetings don't drift to the end of one team's day. These times hold for most of the year, but Barcelona's daylight saving (which Beijing doesn't use) shifts them by an hour twice annually.