Kathmandu is 13.75 hours ahead of Portland
There is no standard 8-to-6 overlap. Someone joins early or late.
A 13.75-hour difference puts Portland and Kathmandu out of sync — when one team is mid-morning, the other is fast asleep. Consider rotating the inconvenience: one week Portland takes the early call, the next week Kathmandu does. Remember that Portland shifts for daylight saving and Kathmandu doesn't, so recalculate the overlap after each clock change.