EI 403 then FR 337 at Dublin
Rome → Dublin → London Luton
Timetable, Dublin time
13:35EI 403 from Rome at the gate
08:00FR 337 to London Luton leaves the gate
18 h 25 apart on the timetable, overnight
FR 337 leaves 18 h 25 after EI 403 arrives on the timetable: more than half a day, so not a connection we count.