Flight Sheremetyevo International Airport departs from Moscow Sheremetyevo International Airport at 23:45 and arrives at Yerevan Zvartnots International Airport at 03:45.
The flighttime is about 3h 00m. The distance travelled ("as the bird flies"): 1536 Km. So the average speed is roughly 512 Km.
There is an 1 hour time difference between Moscow and Yerevan