Originally Posted by
SK2751
I shamefully admit that I lost track of the level of IT support for this feature (same day change on short haul for EBDs/PLUS). I would like to try using it on Monday, where I am booked for an evening departure, but would prefer a late morning departure. Will the option open in the app or on the website at some known point in time? Only on Monday? Should I check in first for my evening departure, or better not to, because I will lose the option?
I am not too eager to go to the airport Monday morning, just to discover that I failed, and need to wait until my evening departure

You can check in, won't affect the function. Sunday evening you will have the option to move to the monday morning flight.
More specific (the exact details I don't know by heart, but can be found in this thread or elsewhere)
Around 22 hours before your original departure, the function will activate in your app. You will be able to see all alternative flights on the day of departure with the conditions
a) the flight has x *) number of seats left in the cabin class you are booked on
b) the departure of the flight is same day as original flight and less than 22-24 hours ahead of the time when you open the function.
Meaning moving to an earlier flight is possible right at the 22-24h mark, and moving to a later flight is possible when that flight is less than 22-24 h away.
*) I found an older note stating this rule to be:
more than 3 hours defore departure 5 seats must be avilable. Less than 3 hours before departure, change is allowed until cabin is full.