Dallas is 13 hours behind Shanghai
There is no standard 8-to-6 overlap. Someone joins early or late.
Dallas is 13 hours behind Shanghai, so their typical working days don't line up at all. Plan on one side joining outside normal hours. A recurring slot that trades off between early mornings and late evenings usually works best. Heads up: because Dallas changes its clocks and Shanghai doesn't, the difference moves by an hour twice a year. Confirm the overlap around the DST switch.