FR 1557 then FR 6921 at Dublin
Manchester → Dublin → Barcelona
Timetable, Dublin time
23:25FR 1557 from Manchester at the gate
18:10FR 6921 to Barcelona leaves the gate
18 h 45 apart on the timetable, overnight
FR 6921 leaves 18 h 45 after FR 1557 arrives on the timetable: more than half a day, so not a connection we count.