Dallas is 1 hour behind Montreal
Best overlap: 9:00 AM to 6:00 PM in Montreal is 8:00 AM to 5:00 PM in Dallas.
If you set up a recurring sync, 9:00 AM to 6:00 PM in Montreal (8:00 AM to 5:00 PM in Dallas) is the natural home for it. Because you share 9 hours of the workday, there's no need to compromise; book the time that suits the meeting, not the map.