Reykjavik is 3 hours behind Doha
Best overlap: 11:00 AM to 6:00 PM in Doha is 8:00 AM to 3:00 PM in Reykjavik.
11:00 AM to 6:00 PM in Doha is when Reykjavik is also working, at 8:00 AM to 3:00 PM their time. The 3-hour gap barely gets in the way — you've got 7 hours of overlap, so pick whatever time fits the agenda.