Most flights from/to Moscow use the following 6 airports
Bykovo Airport
Moscow
Timezone: GMT+3
BKA/UUBB
Chkalovskiy Airport
Moscow
Timezone: GMT+3
CKL/UUMU
Domodedovo International Airport
Moscow
Timezone: GMT+3
DME/UUDD
Ostafyevo International Airport
Moscow
Timezone: GMT+3
OSF/UUMO
Sheremetyevo International Airport
Moscow
Timezone: GMT+3
SVO/UUEE
Vnukovo International Airport
Moscow
Timezone: GMT+3
VKO/UUWW