Dallas is 14 hours behind Seoul

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

Seoul and Dallas are 14 hours apart, and that gap is wide enough that their normal 9-to-5 workdays never quite touch. If you meet regularly, fix one off-hours slot and rotate it between Seoul and Dallas so the burden doesn't fall on one team. Remember that Dallas shifts for daylight saving and Seoul doesn't, so recalculate the overlap after each clock change.