SA 25 then SA 531 at Johannesburg
Harare → Johannesburg → Durban
Timetable, Johannesburg time
07:55SA 25 from Harare at the gate
07:30SA 531 to Durban leaves the gate
23 h 35 apart on the timetable, overnight
SA 531 leaves 23 h 35 after SA 25 arrives on the timetable: more than half a day, so not a connection we count.