Hanoi is 1 hour behind Shanghai
Best overlap: 9:00 AM to 6:00 PM in Shanghai is 8:00 AM to 5:00 PM in Hanoi.
Shanghai and Hanoi overlap from 9:00 AM to 6:00 PM (Shanghai) to the equivalent 8:00 AM to 5:00 PM in Hanoi — that's your meeting window. Hanoi is 1 hour behind Shanghai, yet you get a full 9 hours of shared hours — enough to schedule around lunches, focus time, and preferences with ease.