FR 275 then FR 340 at Dublin
Glasgow → Dublin → London Luton
Timetable, Dublin time
16:50FR 275 from Glasgow at the gate
12:50FR 340 to London Luton leaves the gate
20 h apart on the timetable, overnight
FR 340 leaves 20 h after FR 275 arrives on the timetable: more than half a day, so not a connection we count.