EN 311 then 4Y 900 at Frankfurt
Firenze → Frankfurt am Main → Dubrovnik
Timetable, Frankfurt am Main time
11:55EN 311 from Firenze at the gate
09:254Y 900 to Dubrovnik leaves the gate
21 h 30 apart on the timetable, overnight
4Y 900 leaves 21 h 30 after EN 311 arrives on the timetable: more than half a day, so not a connection we count.