Tehran is 10.5 hours ahead of Vancouver

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

A 10.5-hour difference puts Vancouver and Tehran out of sync — when one team is mid-morning, the other is fast asleep. Consider rotating the inconvenience: one week Vancouver takes the early call, the next week Tehran does. These times hold for most of the year, but Vancouver's daylight saving (which Tehran doesn't use) shifts them by an hour twice annually.