Hanoi is 12 hours ahead of Dallas

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

Dallas and Hanoi are too far apart in time (12 hours) for their workdays to line up during regular hours. For anything urgent, agree on an early-morning or late-night bridge hour in advance so nobody's caught off guard. Just remember Dallas changes its clocks for daylight saving and Hanoi doesn't, so confirm the overlap whenever the seasons turn.