Reykjavik is 2 hours behind Kyiv
Best overlap: 10:00 AM to 6:00 PM in Kyiv is 8:00 AM to 4:00 PM in Reykjavik.
Keep meetings inside 10:00 AM to 6:00 PM in Kyiv — that maps to 8:00 AM to 4:00 PM in Reykjavik. With 8 hours of daily overlap, these two cities are an easy pairing; almost any reasonable hour works. Keep an eye on the calendar — Kyiv observes daylight saving and Reykjavik doesn't, which nudges this window by an hour twice a year.