UA 901 then BA 976 at Heathrow
San Francisco → London → Berlin
Timetable, London time
07:25UA 901 from San Francisco at the gate
07:05BA 976 to Berlin leaves the gate
23 h 40 apart on the timetable, overnight
BA 976 leaves 23 h 40 after UA 901 arrives on the timetable: more than half a day, so not a connection we count.