VS 21 then UA 2025 at Dulles
London → Washington → San Juan
Timetable, Washington time
17:40VS 21 from London at the gate
17:29UA 2025 to San Juan leaves the gate
23 h 49 apart on the timetable, overnight
UA 2025 leaves 23 h 49 after VS 21 arrives on the timetable: more than half a day, so not a connection we count.