Flight Tribhuvan International Airport departs from Kathmandu Tribhuvan International Airport at 23:55 and arrives at Guangzhou Guangzhou Baiyun International Airport at 06:50.
The flighttime is about 4h 55m. The distance travelled ("as the bird flies"): 3105 Km. So the average speed is roughly 632 Km.
There is an 2 hour time difference between Kathmandu and Guangzhou