Nairobi is 2 hours ahead of Hamburg
Best overlap: 8:00 AM to 4:00 PM in Hamburg is 10:00 AM to 6:00 PM in Nairobi.
8:00 AM to 4:00 PM in Hamburg is when Nairobi is also working, at 10:00 AM to 6:00 PM their time. The 2-hour gap barely gets in the way — you've got 8 hours of overlap, so pick whatever time fits the agenda. The window above shifts seasonally: Hamburg keeps daylight saving while Nairobi ignores it.