Best overlap: 4:00 PM to 6:00 PM in Shenzhen is 8:00 AM to 10:00 AM in Edinburgh.
Keep meetings inside 4:00 PM to 6:00 PM in Shenzhen — that maps to 8:00 AM to 10:00 AM in Edinburgh. With overlap this short — around 2 hours — a recurring slot at 4:00 PM in Shenzhen (8:00 AM in Edinburgh) is worth its weight in gold. Finally, Edinburgh observes daylight saving and Shenzhen doesn't, so this window shifts by an hour for part of the year — recheck it each spring and autumn.
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. -