FR 5020 then FR 340 at Dublin
Pisa → Dublin → London Luton
Timetable, Dublin time
15:40FR 5020 from Pisa at the gate
15:00FR 340 to London Luton leaves the gate
23 h 20 apart on the timetable, overnight
FR 340 leaves 23 h 20 after FR 5020 arrives on the timetable: more than half a day, so not a connection we count.