We do not have enough data on this route to provide a reliable graph showing how many days before departure it is the best to book.
However, usually the closer it is to the departure, the more expensive the tickets are.
The cheapest flights you can book on the route Fiumicino (FCO) - Ioannis Kapodistrias (CFU).
There is no direct flight on the route from Rome to Corfu
Il volo con scalo più breve dura 10h 45min.