Karachi is 12 hours ahead of San Diego

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

Karachi is 12 hours ahead of San Diego, so their typical working days don't line up at all. Plan on one side joining outside normal hours. A recurring slot that trades off between early mornings and late evenings usually works best. Watch the DST gap — when San Diego changes its clocks and Karachi stays the same, this window slides by an hour.