Oslo is 1 hour behind Riyadh
Best overlap: 9:00 AM to 6:00 PM in Riyadh is 8:00 AM to 5:00 PM in Oslo.
The hours that work for both Riyadh and Oslo are 9:00 AM to 6:00 PM (Riyadh) and 8:00 AM to 5:00 PM (Oslo). Plenty of room to work with: 9 hours of daily overlap means you can prioritise people's preferences over the clock. One seasonal catch: Oslo springs forward and falls back, but Riyadh doesn't, so the gap changes by an hour for several months of the year.