Islamabad is 10 hours ahead of Atlanta
There is no standard 8-to-6 overlap. Someone joins early or late.
Atlanta and Islamabad are 10 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 Atlanta and Islamabad so the burden doesn't fall on one team. Remember that Atlanta shifts for daylight saving and Islamabad doesn't, so recalculate the overlap after each clock change.