Lagos is 6 hours ahead of Medellín
Best overlap: 8:00 AM to 12:00 PM in Medellín is 2:00 PM to 6:00 PM in Lagos.
The overlap falls at 8:00 AM to 12:00 PM in Medellín, or 2:00 PM to 6:00 PM if you're in Lagos. Lagos is 6 hours ahead of Medellín. That leaves about 4 hours of common time — enough for a meeting or two, so use it deliberately.