Istanbul is 10 hours ahead of San Diego

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

A 10-hour difference puts San Diego and Istanbul out of sync — when one team is mid-morning, the other is fast asleep. Consider rotating the inconvenience: one week San Diego takes the early call, the next week Istanbul does. Remember that San Diego shifts for daylight saving and Istanbul doesn't, so recalculate the overlap after each clock change.