Melbourne is 7 hours ahead of Nairobi
Best overlap: 8:00 AM to 11:00 AM in Nairobi is 3:00 PM to 6:00 PM in Melbourne.
For the smoothest call, aim inside 8:00 AM to 11:00 AM in Nairobi, i.e. 3:00 PM to 6:00 PM in Melbourne. Melbourne is 7 hours ahead of Nairobi, so the practical overlap is about 3 hours — generous enough for meetings, tight enough to be worth booking ahead. Daylight saving complicates things slightly: Melbourne observes it, Nairobi doesn't, so the difference flexes by an hour part of the year.