BR 608 then UA 1580 at O'Hare
Anchorage → Chicago → Boston
Timetable, Chicago time
20:40BR 608 from Anchorage at the gate
12:46UA 1580 to Boston leaves the gate
16 h 06 apart on the timetable, overnight
UA 1580 leaves 16 h 06 after BR 608 arrives on the timetable: more than half a day, so not a connection we count.