UA 926 then 4Y 900 at Frankfurt
San Francisco → Frankfurt am Main → Dubrovnik
Timetable, Frankfurt am Main time
14:55UA 926 from San Francisco at the gate
09:254Y 900 to Dubrovnik leaves the gate
18 h 30 apart on the timetable, overnight
4Y 900 leaves 18 h 30 after UA 926 arrives on the timetable: more than half a day, so not a connection we count.