Flight Tribhuvan International Airport departs from Kathmandu Tribhuvan International Airport at 20:40 and arrives at Colombo Bandaranaike International Airport at 23:25.The flight has a short stop at Kuala Lumpur.
The flighttime is about 3h 15m. The distance travelled ("as the bird flies"): 667 Km. So the average speed is roughly 205 Km.
There is an 0.5 hour time difference between Kathmandu and Colombo