Dallas is 6 hours behind Casablanca
Best overlap: 2:00 PM to 6:00 PM in Casablanca is 8:00 AM to 12:00 PM in Dallas.
Both offices are open during 2:00 PM to 6:00 PM Casablanca time, which is 8:00 AM to 12:00 PM in Dallas. You've got a decent 4-hour window. Set a recurring time near 2:00 PM in Casablanca (8:00 AM in Dallas) and stick to it. Watch the DST gap — when Dallas changes its clocks and Casablanca stays the same, this window slides by an hour.