UO 619 then UO 250 at Hong Kong
Seoul → Hong Kong → Sanya
Timetable, Hong Kong time
15:30UO 619 from Seoul at the gate
08:45UO 250 to Sanya leaves the gate
17 h 15 apart on the timetable, overnight
UO 250 leaves 17 h 15 after UO 619 arrives on the timetable: more than half a day, so not a connection we count.