Air Canada has a change flight policy that allows passengers to modify their flight itinerary. The policy includes both voluntary and mandatory changes, such as flight cancellations or delays. Passengers can make changes to their flight bookings online, through the Air Canada mobile app, or by contacting the airline's customer service center. However, please note that changes may come with fees and charges, depending on the type of fare purchased and the time of the change request. It is recommended to check the terms and conditions of the ticket purchased and the changed policy before making any modifications to the flight itinerary. Overall, Air Canada's change flight policy aims to provide flexibility and convenience to passengers who need to adjust their travel plans.