Makes sense, that would also work. However, there is another case where the question comes: what is the best time for a meeting between San Francisco, New York,

Makes sense, that would also work. However, there is another case where the question comes: what is the best time for a meeting between San Francisco, New York, London, and Berlin for example? Here it becomes a bit challenging as we lost the meaning of local hours for those locations. 2am in most cases means sleeping time, not for everyone, but mostly. With only UTC we'd lose the semantics meaning of local hours. Hence combining local hours and UTC in one clock face.