Islamabad is 13 hours ahead of San Diego
There is no standard 8-to-6 overlap. Someone joins early or late.
Islamabad is 13 hours ahead of San Diego, which is far enough that a normal 9-to-5 in one city never reaches the other's working hours. One practical option: San Diego dials in early while it's still late afternoon or evening in Islamabad. Remember that San Diego shifts for daylight saving and Islamabad doesn't, so recalculate the overlap after each clock change.