Johannesburg and Lusaka are in the same time zone. Both cities use Central Africa Time (CAT, UTC+2). When it's noon in Johannesburg, it's also noon in Lusaka.
Neither city observes daylight saving time.
Any time works! Since both cities are in the same time zone, scheduling is never an issue.
Johannesburg and Lusaka are connected by direct flights taking about 2 hours. South African Airways and other regional carriers operate this route.