Hong Kong is 13 hours ahead of Dallas

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

Dallas and Hong Kong live on different parts of the day. With 13 hours between them, standard working hours simply don't meet. Make the most of handoffs — end-of-day in one city becomes start-of-day in the other, so pass work along rather than meeting live. For part of the year the maths changes: Dallas observes daylight saving, Hong Kong does not, shifting the overlap by an hour.