It says the decision is based on operational considerations and is meant to provide customers with certainty around planning and booking travel.
Air Canada has a fleet of 24 Boeing 737 Max aircraft, which it and other global carriers grounded last March following two fatal crashes of the aircraft.
Boeing advised customers and suppliers Tuesday that it estimates that the plane will remain grounded until mid-year.
Air Canada had earlier opted to push back the return of the aircraft until March 31.
WestJet announced Tuesday that it will remove the plane from its schedule until June 24.
The Calgary-based airline said the change marked the ninth delay of the plane’s return.
WestJet CEO Ed Sims said the airline is confident in the regulatory process undertaken by the Federal Aviation Authority and Transport Canada to ensure the safe return of the aircraft.
The airline says it has completed more than 98 per cent of planned departures even while its 13 Max aircraft remain on the ground.