Hey, you may be interested in my recent Monday Methods post on historical time. First I look at how time concepts became more unified in Europe; then at some theories of time; and lastly at different time measurement of the Aztecs and how they were tranformed through European colonisation.

My focus there is more on calendars and times notions- since your question focuses more on smaller time units you could also check out the very good FAQ section on time (starting with "calendars"). There it's well explained how this measurement is not bizarre but rathet based on natural rhythms and the relative ease of subdividing them - so that this system spread to different parts of the world . While major differences existed these were increasingly leveled through European colonisation and the imposition of European calendars, clocks etc.