Shenzhen is 5 hours ahead of Riyadh
Best overlap: 8:00 AM to 1:00 PM in Riyadh is 1:00 PM to 6:00 PM in Shenzhen.
Both offices are open during 8:00 AM to 1:00 PM Riyadh time, which is 1:00 PM to 6:00 PM in Shenzhen. Roughly 5 hours of common time means scheduling is manageable; just avoid the very edges of the window.