Riyadh is 2 hours ahead of Casablanca
Best overlap: 8:00 AM to 4:00 PM in Casablanca is 10:00 AM to 6:00 PM in Riyadh.
Your shared working hours run 8:00 AM to 4:00 PM in Casablanca (10:00 AM to 6:00 PM in Riyadh). The 2-hour gap barely gets in the way — you've got 8 hours of overlap, so pick whatever time fits the agenda.