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 most popular airlines on the route Tehran - Milan: Ukraine International (PS).
The cheapest flights are on the route Imam Khomeini (IKA) - Malpensa (MXP).
There is no direct flight on the route from Tehran to Milan
Il volo con scalo più breve dura 14h 25min.