Best overlap: 11:00 AM to 6:00 PM in Istanbul is 8:00 AM to 3:00 PM in Edinburgh.
Both teams are at their desks between 11:00 AM to 6:00 PM in Istanbul and 8:00 AM to 3:00 PM in Edinburgh. A 7-hour overlap gives you real choice here — early or late in the window both work comfortably. Note the seasonal wrinkle: when Edinburgh is on daylight saving and Istanbul isn't, the gap between them grows or shrinks by an hour.
London to New York is five hours apart, except for the five weeks a year when it isn't. Exact overlap windows for every US zone, the 2026 DST mismatch dates, and where to put the recurring sync. -