If possible, you need to make it possible for three-5h of transit time in Johannesburg, so that you've got ample time for you to catch your connecting flight. Transiting in Johannesburg is rather easy; just Keep to the indications for ‘Worldwide Transit’. The flight from Johannesburg to Harare takes about https://www.theluxurybooking.co.uk/flights-to-zimbabwe-from-london/