GQ 820 then FR 4437 at Fiumicino
Athens → Rome → Riga
Timetable, Rome time
12:00GQ 820 from Athens at the gate
06:00FR 4437 to Riga leaves the gate
18 h apart on the timetable, overnight
FR 4437 leaves 18 h after GQ 820 arrives on the timetable: more than half a day, so not a connection we count.