EI 3257 then FR 340 at Dublin
Edinburgh → Dublin → London Luton
Timetable, Dublin time
17:40EI 3257 from Edinburgh at the gate
14:40FR 340 to London Luton leaves the gate
21 h apart on the timetable, overnight
FR 340 leaves 21 h after EI 3257 arrives on the timetable: more than half a day, so not a connection we count.