If Possible, you need to make it possible for three-5h of transit time in Johannesburg, so you have sufficient the perfect time to capture your connecting flight. Transiting in Johannesburg is very simple; simply Stick to the symptoms for ‘Global Transit’. The flight from Johannesburg to Harare takes about 1h https://www.theluxurybooking.co.uk/flights-to-zimbabwe-from-london/