Atlanta is 10 hours behind Islamabad
There is no standard 8-to-6 overlap. Someone joins early or late.
Islamabad and Atlanta 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 Islamabad and Atlanta so the burden doesn't fall on one team. Because Atlanta and Islamabad don't both observe daylight saving, plan to re-check the overlap around March and November.