Tehran is 9.5 hours ahead of Calgary

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

When Calgary starts work, Tehran is already winding down or offline — the 9.5-hour gap leaves no shared window. Default to async and only schedule live time when it genuinely needs a conversation — then make it count. Seasonal note: Calgary uses daylight saving and Tehran doesn't, so double-check the times in your own months — they can move by an hour.