Portland is 11.5 hours behind Tehran
There is no standard 8-to-6 overlap. Someone joins early or late.
Tehran and Portland are too far apart in time (11.5 hours) for their workdays to line up during regular hours. For anything urgent, agree on an early-morning or late-night bridge hour in advance so nobody's caught off guard. Just remember Portland changes its clocks for daylight saving and Tehran doesn't, so confirm the overlap whenever the seasons turn.