AZ 621 then FR 4891 at Fiumicino
Los Angeles → Rome → Catania
Timetable, Rome time
12:20AZ 621 from Los Angeles at the gate
11:35FR 4891 to Catania leaves the gate
23 h 15 apart on the timetable, overnight
FR 4891 leaves 23 h 15 after AZ 621 arrives on the timetable: more than half a day, so not a connection we count.