UA 1306 then WN 988 at Denver
Sacramento → Denver → Buffalo
Timetable, Denver time
12:09UA 1306 from Sacramento at the gate
11:50WN 988 to Buffalo leaves the gate
23 h 41 apart on the timetable, overnight
WN 988 leaves 23 h 41 after UA 1306 arrives on the timetable: more than half a day, so not a connection we count.