I can only quote the SAA schedule:
From New York JFK NY US to: Johannesburg Int'l
Non-Stop
SAfrican 202
From:JFK To:JNB
5:55 PM 3:30 PM
14h:35m
744
From Johannesburg Int'l to: New York JFK Int'l NY US
VIA: Sal Amlcar Cabral Int'l CV
SAfrican 201
From:JNB To:SID
8:00 PM 2:05 AM
Con't Flight
From:SID To:JFK
3:25 AM 7:10 AM
18h:10m
744