DL 9941 then UA 609 at Atlanta
Queretaro → Atlanta → Denver
Timetable, Atlanta time
19:43DL 9941 from Queretaro at the gate
16:39UA 609 to Denver leaves the gate
20 h 56 apart on the timetable, overnight
UA 609 leaves 20 h 56 after DL 9941 arrives on the timetable: more than half a day, so not a connection we count.