Riyadh is 2.75 hours behind Kathmandu
Best overlap: 10:45 AM to 6:45 PM in Kathmandu is 8:00 AM to 4:00 PM in Riyadh.
The sweet spot is 10:45 AM to 6:45 PM Kathmandu time, matching 8:00 AM to 4:00 PM in Riyadh. Riyadh is 2.75 hours behind Kathmandu, and with 8 hours of overlap you can even run back-to-back calls without stepping outside business hours.