UA 489 then WN 988 at Denver
Santa Ana → Denver → Buffalo
Timetable, Denver time
12:06UA 489 from Santa Ana at the gate
11:50WN 988 to Buffalo leaves the gate
23 h 44 apart on the timetable, overnight
WN 988 leaves 23 h 44 after UA 489 arrives on the timetable: more than half a day, so not a connection we count.