If Possible, you must permit 3-5h of transit time in Johannesburg, so that you've got enough the perfect time to capture your connecting flight. Transiting in Johannesburg is quite straightforward; basically Adhere to the signals for ‘Intercontinental Transit’. The flight from Johannesburg to Harare can take about 1h 30m. By https://www.theluxurybooking.co.uk/flights-to-zimbabwe-from-london/