CZ 6781 then CZ 3993 at Guangzhou
Sanya → Guangzhou → Changzhou
Timetable, Guangzhou time
09:40CZ 6781 from Sanya at the gate
22:15CZ 3993 to Changzhou leaves the gate
12 h 35 apart on the timetable
CZ 3993 leaves 12 h 35 after CZ 6781 arrives on the timetable: more than half a day, so not a connection we count.