Hanoi is 14 hours ahead of Seattle

There is no standard 8-to-6 overlap. Someone joins early or late.

There's no shared 9-to-5 between Seattle and Hanoi; at 14 hours apart, one city's workday is the other's evening or night. Your best bet is one team taking an early-morning or late-evening call — alternating who stretches keeps it fair over time. These times hold for most of the year, but Seattle's daylight saving (which Hanoi doesn't use) shifts them by an hour twice annually.