Ottawa is 18 hours behind Wellington
Best overlap: 8:00 AM to 12:00 PM in Wellington is 2:00 PM to 6:00 PM in Ottawa.
For the smoothest call, aim inside 8:00 AM to 12:00 PM in Wellington, i.e. 2:00 PM to 6:00 PM in Ottawa. Ottawa is 18 hours behind Wellington, so you've got a workable 4-hour overlap — ideal for a standing meeting around 8:00 AM in Wellington (2:00 PM in Ottawa). Because Ottawa is on the previous day, weekend boundaries can shift; check that neither side is meeting on their day off.