Lima is 3 hours ahead of Portland
Best overlap: 8:00 AM to 3:00 PM in Portland is 11:00 AM to 6:00 PM in Lima.
Target 8:00 AM to 3:00 PM in Portland, which lands at 11:00 AM to 6:00 PM for the Lima side. That's a roomy 7 hours of common time each day, so finding a slot that suits everyone is rarely a problem. Note that Portland follows daylight saving while Lima stays put, so the times above drift by an hour seasonally.