The cheapest day to depart on your flight to Istanbul is on a Wednesday when prices can be found for as low as 1,235 C$. This is often the case because there is less demand to fly during this day of the week. Flights from Canada to Istanbul on a Sunday will generally be more expensive and average around 1,354 C$. Keep in mind that these prices on both days could fluctuate depending on the season and the demand.
The cheapest time of day to fly to Istanbul is in the morning when flights can be purchased for as low as 1,090 C$. At noon is when there is more demand to fly to Istanbul, so prices are often more expensive at around 1,371 C$ per ticket.