Tehran is 10.5 hours ahead of San Diego

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

There's no shared 9-to-5 between San Diego and Tehran; at 10.5 hours apart, one city's workday is the other's evening or night. Your best bet is one team taking an early-morning or late-evening call — alternating who stretches keeps it fair over time. Keep an eye on the calendar — San Diego observes daylight saving and Tehran doesn't, which nudges this window by an hour twice a year.