Johannesburg is 3.75 hours behind Kathmandu
Best overlap: 11:45 AM to 6:45 PM in Kathmandu is 8:00 AM to 3:00 PM in Johannesburg.
If you set up a recurring sync, 11:45 AM to 6:45 PM in Kathmandu (8:00 AM to 3:00 PM in Johannesburg) is the natural home for it. Despite the 3.75-hour difference, a 7-hour overlap keeps things simple and gives both teams breathing room.