Decimal time and hexadecimal time are two rival ways to divide the day. The first is most famous from the French Revolution, where a decimal time french revolution scheme was introduced. Both rework how hours, minutes, and seconds are counted, separate from binary clocks that keep ordinary 24/60/60 divisions and write them in base 2.

Decimal Time and the French Revolution

The most notable attempt to implement decimal time came during the French Revolution. The French Revolutionary decimal time divided the day into 10 hours, each hour into 100 minutes, and each minute into 100 seconds. This created a metric time structure where the entire day ran on powers of 10.

This became official in France in 1794. Mandatory use was suspended in 1795. The change was short-lived, but it remains the most famous example of a decimal time scheme being put into practice.

How Decimal Time Measured the Day

Under the French Revolutionary decimal time scheme, the day was split into 10 equal parts called decimal hours. Each decimal hour was further divided into 100 decimal minutes, and each decimal minute into 100 decimal seconds. To see how this relates to the ordinary day, use these conversions:

  • There are 86,400 ordinary seconds in a day. Under decimal time, there are 100,000 decimal seconds in a day.
  • One decimal second equals 0.864 ordinary seconds.
  • One decimal hour equals 2.4 ordinary hours.

The Concept of a 10 Hour Day

The 10 hour day is central to decimal time. Instead of the familiar 24 hour cycle, a decimal day has only 10 hours. This is a form of metric time, where all units relate by factors of 10. Learn the French Revolutionary structure first, then apply the same logic to other 10 hour day proposals that aimed to simplify timekeeping.

Hexadecimal Time

Another alternative time scheme is hexadecimal time. This divides the day into 16 hexadecimal hours. John W. Nystrom proposed it in 1863. Instead of base 10, it uses base 16, which suits computing and digital work better.

The Structure of Hexadecimal Time

In a hexadecimal time scheme, the day is divided into 16 equal parts called hexadecimal hours. Each hexadecimal hour divides into 16 minutes, and each minute into 16 seconds, creating a fully base 16 time structure. Compare this directly with the decimal scheme to see where the two part ways.

Comparing Alternative Time Systems

To compare these alternative time schemes, check how they differ from the ordinary 24/60/60 structure and from each other.

Key Differences

  • Decimal Time: Divides the day into 10 hours, 100 minutes per hour, and 100 seconds per minute. Based on powers of 10.
  • Hexadecimal Time: Divides the day into 16 hours, 16 minutes per hour, and 16 seconds per minute. Based on powers of 16.
  • Binary Clocks: A pure binary clock still uses the ordinary 24/60/60 divisions, only written in base 2. It does not change how the day is divided.

Why These Systems Were Proposed

The motivation behind alternative time schemes like decimal and hexadecimal time is to create a more logical or mathematically consistent way to measure time. The French Revolutionary decimal time was part of a broader push for metric time and decimalization of measurements. The 10 hour day simplifies calculations, as all time units are multiples of ten. Hexadecimal time was proposed to align with a base 16 number system, which has advantages in certain technical fields.

The Legacy of Alternative Time Systems

Neither decimal time nor hexadecimal time replaced the standard 24 hour day. The French Revolutionary decimal time lasted only about a year as a mandatory structure. These schemes remain interesting historical and intellectual exercises. They show that the way we divide the day is a human choice, not a natural law. To see time represented differently, visit a site like binclock.com for a live BCD binary clock that uses the ordinary 24/60/60 divisions but displays them in binary.