Revolutionary Time

This is not a mistake, nor is it a line from a science fiction film; it is merely an exchange that could have taken place between two gentlemen in 18th century France. Indeed, the French Revolution attempted to change the way time was told. On November 24, 1793, a decree of the Convention Nationale instituted a decimal division of time, which was in accord with the metric system that had been adopted by the new nation.

The Gregorian calendar, created by Pope Gregory XII in 1582, was thus replaced by the Republican calendar, in which a year comprised 12 months, each 30 days in length, and an additional month made up of 5 days (6 days during leap years).

Each month contained 3 decades of 10 days each. The days were called primidi, duodi, tridi, quartidi, quintidi, sextidi, septidi, octidi, nonodi, décadi. In practical terms, the day was no longer divided into 24 hours, but into 10 hours of 100 minutes each, each minute being comprised of 100 seconds. A revolutionary hour thus was equal to 2 hours and 20 minutes of a normal hour.

Since the reform was difficult to enforce and was not easily accepted by the populace, many watches of the time featured a double display of both Revolutionary and “classical” time. If the watch had only one dial, two different colors, one for each system, might be used to distinguish between the decimal and duo-decimal displays. If the watch had more than one dial, these were often decorated with patriotic symbols of the Revolution, such as Marianne, dancers of the Carmagnole, or the Phrygian bonnet.

by the population. It is not easy to change people’s habits, nor to modify their relationship with time.

Proof of this is the recent attempt made by the Swatch firm to establish a new international time standard for users of the internet in order to abolish the constraints of time zones. The idea, which divided the day into 1000 equal “.beats” was not a resounding success.

Given the difficulty encountered in applying the law on
Revolutionary time, on August 22, 1794, the authorities of the new Republic held a contest aimed at encouraging watchmakers and scientists to discover economically viable solutions that would allow existing watches to be transformed to the decimal system, while still conserving the
duodecimal indications. Such prestigious horological names as Ferdinand Berthoud, Antide Janvier, and Jean Antoine Lépine made up the jury. But despite the many ingenious systems proposed, the contest did not achieve its stated goal, that of encouraging the development of the decimal system, and even less that of making it popular.

On April 7, 1795, a new decree suspended the law that had made the decimal time system obligatory. The authorities of the time had become aware that the population was
having too much difficulty accepting the system, and that it
condemned watchmakers to producing only for the national market. Thus, Revolutionary watches were only produced for a period of 18 months. The Republican calendar remained in occasional use until the beginning of the Empire, then was abolished by Napoleon on January 1, 1806.

Revolutionary watches are rare and unusual, made in small series, and thus have their place in any good collection.

And they will allow you to answer, when someone asks you the time:

“It is 4:88 and 90 seconds”!