Response to Scientific American and Connor & Robertson's (2000) Articles on History of Time Calculations

    When I think about the relationships among concepts of time, I often visualize them as interconnected fractions. For example, if we represent a year as a bar, it can be divided into four equal segments, each corresponding to a season (spring, summer, fall, winter). Each season represents 1/4 of the year, with the months grouped as January to March, April to June, July to September, and October to December. However, when I lived in Vietnam, I thought of a year differently—split into two seasons: the dry season from September to February and the rainy season from March to August, where each season represented 1/2 of the year. Similarly, I picture hours and minutes on a clock, divided into four quarters of 15 minutes or seconds. This recurring image of time as neat fractions highlights how intuitive and functional base 12 and base 60 systems are compared to our typical base 10.

    I was intrigued to learn from a Scientific American article that the concept of fixed hours is relatively modern, and that hours varied in length in the past. I had often wondered—but never explored—why we divide the day into 24 equal hours. Why not 12 or 60? And how did people account for the long days and nights that vary with the seasons? At the time fixed-length hours were introduced, this must have seemed like a radical idea, especially in regions far from the equator where day and night lengths fluctuate greatly. Reading about the historical shift toward dividing days and nights into 12 equal parts felt intellectually satisfying to me. While it might seem artificial or "forced" to impose such regularity on something as variable as the length of daylight, this decision reflects humanity’s intrinsic drive for patterns and consistency. It’s a fascinating example of how we adapt natural phenomena to fit our calculation systems, supported by both astronomy and the practical needs of daily life.