DL 516 then DL 2597 at Atlanta
Dallas → Atlanta → Montréal
Timetable, Atlanta time
09:15DL 516 from Dallas at the gate
09:00DL 2597 to Montréal leaves the gate
23 h 45 apart on the timetable, overnight
DL 2597 leaves 23 h 45 after DL 516 arrives on the timetable: more than half a day, so not a connection we count.