FR 3881 then EI 172 at Dublin
Dubrovnik → Dublin → London Heathrow
Timetable, Dublin time
23:05FR 3881 from Dubrovnik at the gate
15:30EI 172 to London Heathrow leaves the gate
16 h 25 apart on the timetable, overnight
EI 172 leaves 16 h 25 after FR 3881 arrives on the timetable: more than half a day, so not a connection we count.