Riyadh is 3 hours ahead of Reykjavik
Best overlap: 8:00 AM to 3:00 PM in Reykjavik is 11:00 AM to 6:00 PM in Riyadh.
Book within 8:00 AM to 3:00 PM Reykjavik time (11:00 AM to 6:00 PM in Riyadh) and both teams will be at work. The overlap is wide at 7 hours, so you can protect mornings for deep work and still find plenty of meeting time.