FR 839 then FR 6842 at Manchester
Porto → Manchester → Prague
Timetable, Manchester time
11:40FR 839 from Porto at the gate
08:25FR 6842 to Prague leaves the gate
20 h 45 apart on the timetable, overnight
FR 6842 leaves 20 h 45 after FR 839 arrives on the timetable: more than half a day, so not a connection we count.