UA 604 then M6 5771 at Houston
San Francisco → Houston → Louisville
Timetable, Houston time
06:32UA 604 from San Francisco at the gate
06:30M6 5771 to Louisville leaves the gate
23 h 58 apart on the timetable, overnight
M6 5771 leaves 23 h 58 after UA 604 arrives on the timetable: more than half a day, so not a connection we count.