Originally Posted by
hydrogen
In order to upgrade, seats must be available AND you need to be within your upgrade window.
The AC website only shows if seats are available. If seats are available for upgrade for a flight in 3 months, they may not necessarily be available once you are within your upgrade window.
The window for 35K is 8 days. 10 days for 50K, 12 for 75K, and 14 for 100K.
The windows are actually 4,5,6,7 days, however AirCanada has had a continuous program of "promos" due to weak J sales doubling the window.