Reykjavik is 1 hour behind Geneva
Best overlap: 9:00 AM to 6:00 PM in Geneva is 8:00 AM to 5:00 PM in Reykjavik.
Geneva and Reykjavik overlap from 9:00 AM to 6:00 PM (Geneva) to the equivalent 8:00 AM to 5:00 PM in Reykjavik — that's your meeting window. 9 hours of shared hours is more than enough — slot meetings wherever they're most convenient for the people involved. A quick caveat — Geneva's clocks move for daylight saving and Reykjavik's don't, so the times here are right for only part of the year.