UA 1897 then DL 991 at LAX
Washington → Los Angeles → New York JFK
Timetable, Los Angeles time
11:54UA 1897 from Washington at the gate
11:25DL 991 to New York JFK leaves the gate
23 h 31 apart on the timetable, overnight
DL 991 leaves 23 h 31 after UA 1897 arrives on the timetable: more than half a day, so not a connection we count.