FR 3977 then BT 684 at Barcelona
Dublin → Barcelona → Riga
Timetable, Barcelona time
22:55FR 3977 from Dublin at the gate
14:05BT 684 to Riga leaves the gatealso IB 7848
15 h 10 apart on the timetable, overnight
BT 684 leaves 15 h 10 after FR 3977 arrives on the timetable: more than half a day, so not a connection we count.