Dallas is 12 hours behind Hanoi

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

Coordinating Hanoi and Dallas is tricky: 12 hours of separation means their standard hours don't intersect. Async-first is your friend here. Reserve real-time meetings for the rare occasions someone can log on before or after hours. Heads up: because Dallas changes its clocks and Hanoi doesn't, the difference moves by an hour twice a year. Confirm the overlap around the DST switch.