Istanbul is 1 hour ahead of Rome

Best overlap: 8:00 AM to 5:00 PM in Rome is 9:00 AM to 6:00 PM in Istanbul.

Aim for 8:00 AM to 5:00 PM Rome time — that's 9:00 AM to 6:00 PM over in Istanbul. Because you share 9 hours of the workday, there's no need to compromise; book the time that suits the meeting, not the map. Remember that Rome shifts for daylight saving and Istanbul doesn't, so recalculate the overlap after each clock change.