Perhaps I am the last to know this (and no, I didn’t read the fine print)…
I upgrade my airline tickets to ones that offer a credit should you cancel. Just recently I had to cancel our RS tour and flights just three weeks out from leaving due to a serious auto accident. I assumed I had a year’s credit on the airline tickets, but the year starts from the purchase date, not the cancellation date. If you are like me and purchase your airline tickets the year prior to grab a good price, the clock has been ticking on your credit period.
It depends on which airline tickets you buy, but yes, that is usually the case. Many airlines expanded that period during the Covid pandemic, but most have gone back to expiring one year from the purchase date.
Yes, I found out the hard way, too.
I would seek clarification on how the credit works. For example do you have to actually purchase and fly before the expiration date or do you have to utilize the credit before the expiration date for which travel can be scheduled beyond that date. The latter has been my experience.
Due to life circumstances, I am in possession of a LOT of Delta credit. It expires in March 2025 but I only need to book travel by then...not actually take the trip. YMMV but this is how it played out for us.