FR 4113 then FR 8837 at Fiumicino
Katowice → Rome → Zagreb
Timetable, Rome time
20:00FR 4113 from Katowice at the gate
12:00FR 8837 to Zagreb leaves the gate
16 h apart on the timetable, overnight
FR 8837 leaves 16 h after FR 4113 arrives on the timetable: more than half a day, so not a connection we count.