Portland is 9 hours behind Rome
Best overlap: 5:00 PM to 6:00 PM in Rome is 8:00 AM to 9:00 AM in Portland.
For a call that suits both sides, look at 5:00 PM to 6:00 PM in Rome / 8:00 AM to 9:00 AM in Portland. Since Portland is 9 hours behind Rome, the overlap is narrow (about 1 hour); a single, well-protected slot beats hunting for time each week.