Phoenix is 10 hours behind Cairo

There is no standard 8-to-6 overlap. Someone joins early or late.

Phoenix is 10 hours behind Cairo, which is far enough that a normal 9-to-5 in one city never reaches the other's working hours. One practical option: Phoenix dials in early while it's still late afternoon or evening in Cairo. Remember that Cairo shifts for daylight saving and Phoenix doesn't, so recalculate the overlap after each clock change.