As I wrote before in other threads, size of Iran is more than California, Texas and New York State put together, is covered with mountains (large part of territory is above 5,000 feet) and has 70 million people.
How do you imagine the attack?
Easy.
Bombardment of known nuclear facilities: one week.
Insertion/Extraction of follow-up Spec-Ops demolition teams: one week.
Destruction of all command and control infrastructure: (Concurrent with first week): One week.
Decapitation of leadership: (Concurrent with first week) two weeks.
Cordon of major oil producing fields in the south: TBD.
Any questions?