Islamabad is 11 hours ahead of Houston
There is no standard 8-to-6 overlap. Someone joins early or late.
Islamabad is 11 hours ahead of Houston, 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. Because only Houston changes its clocks, the overlap above isn't fixed; expect a one-hour shift when Houston enters or leaves daylight saving.