DL 5731 then UA 723 at Boston
Pittsburgh → Boston → Houston
Timetable, Boston time
18:44DL 5731 from Pittsburgh at the gate
17:17UA 723 to Houston leaves the gate
22 h 33 apart on the timetable, overnight
UA 723 leaves 22 h 33 after DL 5731 arrives on the timetable: more than half a day, so not a connection we count.