UA 1591 then UA 1453 at San Francisco
San Antonio → San Francisco → Washington
Timetable, San Francisco time
11:02UA 1591 from San Antonio at the gate
16:52UA 1453 to Washington leaves the gatealso VA 8383, NZ 9169
5 h 50 apart on the timetable
The last days
UA 1591 and UA 1453 weren’t both flown 15 min to 12 h apart in the last 21 days.
Statistics from past flights, not live flight information. Always check times and your connection with your airline, and don’t base travel or booking decisions on these numbers.