Islamabad is 11 hours ahead of Dallas
There is no standard 8-to-6 overlap. Someone joins early or late.
The 11-hour difference means Dallas and Islamabad miss each other entirely during regular office hours. Where you can, lean on async updates and save live calls for when one team is happy to start early or stay late. For part of the year the maths changes: Dallas observes daylight saving, Islamabad does not, shifting the overlap by an hour.