Customers who booked an Air Canada flight on or before Aug. 15 for travel on Saturday or Sunday can cancel for a full refund of the unused portion of their ticket, regardless of fare type, through the company’s website or mobile app. Travelers may also opt for a travel credit to use toward a future Air Canada booking.

A walkout by flight attendants ended after about 12 hours with the imposition of binding arbitration. But getting travel back to normal will take days.

A bitter contract fight between Canada’s largest airline and the union representing its flight attendants escalated Friday.