EI 136 then FR 3977 at Dublin
Boston → Dublin → Barcelona
Timetable, Dublin time
08:20EI 136 from Boston at the gate
07:40FR 3977 to Barcelona leaves the gate
23 h 20 apart on the timetable, overnight
FR 3977 leaves 23 h 20 after EI 136 arrives on the timetable: more than half a day, so not a connection we count.