Best overlap: 2:00 PM to 6:00 PM in Portland is 8:00 AM to 12:00 PM in Brisbane.
Portland and Brisbane overlap from 2:00 PM to 6:00 PM (Portland) to the equivalent 8:00 AM to 12:00 PM in Brisbane — that's your meeting window. The shared window is roughly 4 hours; treat its midpoint as the default and you'll keep both teams happy. Keep the date straight: Brisbane is on the next day versus Portland, which can trip up Friday or Monday meetings. One seasonal catch: Portland springs forward and falls back, but Brisbane doesn't, so the gap changes by an hour for several months of the year.
The US to Australia gap runs 14 to 19 hours depending on the month, and someone is always in tomorrow. Exact overlap windows for every US coast, the double-DST trap, and a rotation rule that keeps it fair. -