DL 514 then WN 577 at Phoenix
Boston → Phoenix → Las Vegas
Timetable, Phoenix time
21:53DL 514 from Boston at the gate
12:55WN 577 to Las Vegas leaves the gate
15 h 02 apart on the timetable, overnight
WN 577 leaves 15 h 02 after DL 514 arrives on the timetable: more than half a day, so not a connection we count.