Glasgow and London are in the same time zone. Both cities use GMT in winter and BST in summer. When it's noon in Glasgow, it's also noon in London.
Both cities observe daylight saving time together.
Any time works! Since both cities are in the same time zone, scheduling is never an issue.
Glasgow and London are connected by frequent trains (4.5 hours) and short flights (1 hour). Glasgow is Scotland's largest city and a major economic center.