Dallas is 7 hours behind Copenhagen
Best overlap: 3:00 PM to 6:00 PM in Copenhagen is 8:00 AM to 11:00 AM in Dallas.
For the smoothest call, aim inside 3:00 PM to 6:00 PM in Copenhagen, i.e. 8:00 AM to 11:00 AM in Dallas. Since Dallas is 7 hours behind Copenhagen, the workdays overlap by around 3 hours; 3:00 PM in Copenhagen (8:00 AM in Dallas) makes a reliable recurring slot.