I was just reading through SAS's Diamond perks, and they have – to my understanding – implemented this in quite a nice way. Pick any flight at the same departure day, but request it already when checkin is open. Would be good if AFKL adopts this too, because I agree with
Mike_Paris that 'you need to call on same day' can be very inconvenient for some flight times.
SAS Explanation:
As a Diamond member, you have the possibility to change your flight (to an earlier or later departure) free of charge on the day of departure. This benefit applies to all SAS flights regardless of ticket type.
Rebooking is done via the SAS App and free changes only apply at segment level, they cannot be used to change your itinerary. Standard ticketing rules will apply once the scheduled departure time has elapsed.
Good to know:- You can change a flight from when check-in opens up until 80 minutes before departure.
- Changing a flight only applies to flights on the same day and applies to all travelers in your booking.
- If you change your flight, you’ll lose all added extras e.g. pre-selected seats or meals.
- Change of flight is not possible if you already have checked in a bag.