3U 8121 then CZ 2133 at Guangzhou
Chongqing → Guangzhou → Xining
Timetable, Guangzhou time
16:253U 8121 from Chongqing at the gate
16:15CZ 2133 to Xining leaves the gate
23 h 50 apart on the timetable, overnight
CZ 2133 leaves 23 h 50 after 3U 8121 arrives on the timetable: more than half a day, so not a connection we count.