Reykjavik is 1 hour behind Oslo
Best overlap: 9:00 AM to 6:00 PM in Oslo is 8:00 AM to 5:00 PM in Reykjavik.
For a call that suits both sides, look at 9:00 AM to 6:00 PM in Oslo / 8:00 AM to 5:00 PM in Reykjavik. Despite the 1-hour difference, a 9-hour overlap keeps things simple and gives both teams breathing room. These times hold for most of the year, but Oslo's daylight saving (which Reykjavik doesn't use) shifts them by an hour twice annually.