CA 844 then CA 791 at Beijing
Vienna → Beijing → Xi'an
Timetable, Beijing time
10:25CA 844 from Vienna at the gate
12:55CA 791 to Xi'an leaves the gate
2 h 30 apart on the timetable
The last days
CA 844 and CA 791 weren’t both flown 15 min to 12 h apart in the last 21 days.
Statistics from past flights, not live flight information. Always check times and your connection with your airline, and don’t base travel or booking decisions on these numbers.