In this lighthearted exploration of decimal (or "metric") time, we explore the merits of the system and why it isn't used today. The metric system is the world's official measuring standard. Its consistent base-10 design led to widespread adoption and makes unit conversions easy. It's often praised as the best way to measure, and many go as far as to argue it should replace all other systems... So why do all metric societies still use base-24 and base-60 to tell time? The official SI unit for time is the second, which is already base-10. The problem? Seconds are too small for use in day-to-day scheduling. To make time more human-friendly, we group seconds into minutes and hours. Neither hours nor minutes are base-10, making converting between them a mental math challenge. The fix may seem obvious. Since the metric system is so effective, we'll extend it's philosophy to timekeeping. We'll redefine our units like so: 1 day = 10 metric hours 1 metric hour = 100 metric minutes (1 myriasecond) 1 metric minute = 100 metric seconds (1 hectosecond) We carefully balance metric philosophy and familiarity. Since we can't change the length of a day on Earth, we'll shorten the second instead. This gives us 10 hour days. 10 is close to 12, so the metric clock is visually familiar, but it comes with all the ease of base-10 calculations. How many seconds are in 3 days? Standard: 3 days × 24 hrs × 60 mins × 60 secs = 259,200 seconds Metric: 3 days × 10 hrs × 100 mins × 100 secs = 300,000 metric seconds How many seconds are in an 5 hours? Standard: 5 hrs × 60 mins × 60 secs = 18,000 seconds Metric: 5 hrs × 100 mins × 100 secs = 50,000 metric seconds Sure enough, this new system is much easier to use! So... why are we still using 24-hour days? The answer lies in outer space. Earth takes about 365 times longer to orbit the sun than it does to rotate once. 365 is not a power of ten, so days and years can't be aligned to the metric system. Days and years are the two most important amounts of time to human society, and we can't live without one of the two to make the system work. We need the day to dictate when we work, eat, and sleep, and the yearly cycle of the seasons is critical for agriculture. Aside from the astrophysics issues, tradition and quality of life are also important. A 10-day week with 8 consecutive working days is unacceptable to most, and the meaning of "annual" could become ambiguous, referring either to some newly chosen year length or the solar-based 365-day cycle. These problems are technically fixable, but they were still important reasons for metric time's past failures to gain traction. The system this project showcases is similar to French Revolutionary Time, one of the most recent attempts to bring timekeeping into base-10. The concept is more widely known as "Decimal Time", and it has been used and abandoned by several parts of the world throughout history. If you're interested in learning more about the historical attempts to metricize time, Wikipedia may be a good place to start: https://en.wikipedia.org/wiki/Decimal_time
