Johannesburg is typically 2 hours ahead of London. When it's 12:00 PM in London, it's 2:00 PM in Johannesburg. South Africa uses SAST (UTC+2) year-round and does not observe daylight saving time.
During UK summer time (March to October), the difference is only 1 hour. During UK winter time (October to March), Johannesburg is 2 hours ahead.
Excellent overlap! 9:00 AM - 5:00 PM London corresponds to 10:00 AM - 6:00 PM Johannesburg (UK DST) or 11:00 AM - 7:00 PM (UK winter). Nearly full business day overlap.
Johannesburg is Africa's financial capital. British Airways and South African Airways operate multiple daily flights on this historic route connecting two Commonwealth nations.