Flight Leonardo da Vinci–Fiumicino Airport departs from Rome Leonardo da Vinci–Fiumicino Airport at 22:55 and arrives at Moscow Sheremetyevo International Airport at 03:40.
The flighttime is about 3h 45m. The distance travelled ("as the bird flies"): 3133 Km. So the average speed is roughly 835 Km.
There is an 1 hour time difference between Rome and Moscow