Originally Posted by ATLawyer

People are doing a horrible job of explaining this to you. I'm sorry.

It sounds like you have 2 flights: BRU-JFK and JFK-XXX on separate tickets but all in first/business (premium cabin). You are concerned that the ~2 hours between landing in and departing JFK won't be enough time, and you'll miss JFK-XXX. There is a later JFK-XXX which you can get on, which would normally happen automatically if it was the same ticket, but it's separate tickets so you are worried.

Your SDC options are very simple. You have a seat in the premium cabin JFK-XXX, which means that at ANY TIME t-24 from your ORIGINAL flight, you can call in and CONFIRM a seat change to any other JFK-XXX flight leaving the same day as the original. Because you have no status, this will cost you $50 (per ticket). Note that a premium cabin seat must be available on the flight you want to change to, this is the ONLY requirement, and generally even if there isn't a premium seat, they will offer you coach.

So, sounds like there is a 3pm and 6pm JFK-XXX. If you want to change to the later one, call delta at 3pm (time at location of departure) the day before departure, and change to the 6pm. You can make this change any time during that 24 hour window, but NOT after the 3pm flight departs. So, I'd do it in BRU, not waiting to land in JFK.

Originally Posted by orca15

To explain SDC even a little more, it is the process of calling within 24 hours of a flight and changing to another flight that leaves the same day. Your change is confirmed when you call, as opposed to being standby at the gate, so you know you have a seat. There are fare class restrictions for economy fares, but F fares are more flexible.

That was in ATL's response, but I thought a general description might help.

Originally Posted by MSPeconomist

We should also point out to the OP that when SDC is done, the seat on the original flight is lost. You might be able to SDC again back to the original (earlier in this case) flight, but there might not be space.