Montreal is 7 hours behind Istanbul
Best overlap: 3:00 PM to 6:00 PM in Istanbul is 8:00 AM to 11:00 AM in Montreal.
The overlap falls at 3:00 PM to 6:00 PM in Istanbul, or 8:00 AM to 11:00 AM if you're in Montreal. Roughly 3 hours of common time means scheduling is manageable; just avoid the very edges of the window. The window above shifts seasonally: Montreal keeps daylight saving while Istanbul ignores it.