UA 1553 then DL 972 at LAX
San José (Costa Rica) → Los Angeles → New York JFK
Timetable, Los Angeles time
11:08UA 1553 from San José (Costa Rica) at the gate
08:25DL 972 to New York JFK leaves the gate
21 h 17 apart on the timetable, overnight
DL 972 leaves 21 h 17 after UA 1553 arrives on the timetable: more than half a day, so not a connection we count.