Edinburgh and Manchester are in the same time zone. Both cities use Greenwich Mean Time (GMT) in winter and British Summer Time (BST) in summer. When it's noon in Edinburgh, it's also noon in Manchester.
Both cities observe daylight saving time together, switching between GMT (UTC+0) and BST (UTC+1).
Any time works! Since both cities are in the same time zone, scheduling calls is never a problem. Business hours are identical.
Edinburgh and Manchester are connected by frequent trains taking about 3.5 hours and short flights. Both are major UK business centers.