To establish a new Republican identity, French revolutionaries replaced monarchical and religious symbols with 'enlightenment' imagery and introduced a decimal based calender (1793–1805).
Revolution clock dials divided the day into 10 hours of 100 minutes, aligning timekeeping with the decimal system. Horologists however, preserved traditional timekeeping by combining decimal and traditional time displays in a hybrid format.

The system was never really adopted and horologists had no real reason to fully support it, because their Revolution clocks and watches were useless outside France which ruined their export trade.

TABLE OF CONTENTS

Index

Appendix.

Calendar & time.

Dials.

Republican <-> Gregorian conversion.

The Metric System

Names of the days of the Republican year.

The Republican calendar and decimal time

Symbols explained.

Sources & further reading.
 

The hybrid design of revolutionary dials reflects the socio-cultural resistance to time decimalization.
To ensure marketability, watchmakers typically integrated traditional chapters alongside decimal ones. Consequently, timepieces featuring exclusive decimal chapters are exceptionally scarce due to their initial lack of commercial viability.

 

(click to enlarge)

 Combined
traditional & decimal chapters¹

  SOME SYMBOLS EXPLAINED.

The 1789 Revolutionaries adopted a cap worn by ancient Persian soldiers, Thracians and the inhabitants of Phrygia, as they saw it as a symbol of liberation i.e. being freed and purified of evil. They wore a high woollen cap, often falling over the right side of the head.
Its revolutionary significance stemmed from Roman custom, where newly emancipated slaves donned the cap to signify their transition to full citizenship.
 

The Phrygian cap first appeared on the heads of French citizens a few months after the storming of the Bastille. Paired with the striped clothing of the most ardent lower-class revolutionaries the sans-culottes, so called because they did not wear the knee breeches of the upper classes. The red cap became a visible symbol of revolutionary fervor. Wearing it was a public declaration of one’s patriotism. 

This cap was one of the star features of the historic day of 20th June 1792, when the common people surged into the Tuileries. In the angry crowd, which managed to reach the king himself, a municipal guard called Mouchet held out a Phrygian cap, on the end of a pike, to the monarch. The astounded descendant of Saint Louis did not know how to react. He grasped it and put it on his head. This gesture somewhat appeased the hostility of the assailants.

It appears on (Comtoise) clocks during the early royal period, the 'restoration'  (1814-1830) to express the (re)union of the people and their King. (symbole de l'union de trois ordres puis de peuple et de son Roi. Ref. René Schopping) 

It also represents fraternity and equality among citizens — a society without hierarchy, where individuals relate to one another as equals.

The word fasces means “bundle” and refers to the bound rods encircling an axe at the center. In ancient Rome, lictors carried the fasces before consuls, praetors, and dictators—magistrates who held imperium, the supreme authority to command and to take the auspices (interpret the flight of birds).

Fasces surmounted by a Phrygian cap. Power to the liberated people.

Note: Fasces has also been the symbol of Italian fascists in the 20th century.

1799-1804 Eagle Consulaire      Imperial Eagle 1804-1814

An Imperial  emblem.  In Greek mythology the Eagle was attributed to Zeus (Jupiter)

One of the national emblems of France, the Coq Gaulois (the Gallic Rooster) decorated French flags during the Revolution. It is the symbol of the French people because of the play on words of the Latin gallus meaning Gaul and gallus meaning 'coq', or rooster.
Caesar called, what was later France, Gallia (Gaul), most likely because the rebellious Celts used a rooster as symbol in their escutcheon.

The rooster played an important role as the revolutionary symbol, but it would become an official emblem under the July Monarchy and the Second Republic when it was seen on the pole of regiments' flags. In 1830, the "Gallic Rooster" replaced the fleur-de-lis as the national emblem, and it was again discarded by Napoleon III.

The rooster is the emblem of (sponsored) French sports teams in international competitions.
 

Restoration period. 

The French Restoration (1814–1830) was the period after Napoleon’s fall when the Bourbon monarchy was restored under Louis XVIII and Charles X, attempting to re-establish royal authority while retaining some revolutionary and Napoleonic reforms.

Note: Royal sunburst in stead of a cockerel.

A popular rather filthy song and dance, often around a liberty tree, against the imprisoned Royal Family.

Anchor - Hope
Bagpipe - Peace
Bastille - Emblem of the people conquering tyranny
Bishop's cross - Clergy
Broken chain- Abolishment of slavery
Canon - The Revolutionary power
Carmagnole - Popular republican song and dance
Clasped hands - Fraternity
Corn (horn of plenty) - Nature's abundance
Corn sheaf - Abundance, Prosperity
Crown - Monarchy
Eye - Vigilance
Fame - Announcer
Fasces - Unity, Brotherhood, Power.  1)
Flag - The Nation
Fleur de Lys - Monarchy
France - The country (patriotic)
Globe - Universality
Guillotine - Revolutionary justice
Hive - The working class
Laurel (wreath) - Victory
Lion - Power
Oak - Civil virtue
Palm (branch) - Victory of the armies.
Phrygian cap - Symbol of liberty
Pique Pike - The people
Rake - The third estate or commonalty
Rooster (cockerel) - Vigilance
Rosette Cocarde tri-colour  - Emblem of the patriots
Rosette black  - Emblem of the Queen
Rosette white  - Emblem of the Royalists
Scale - Justice
Spade - The third estate or commonalty
Star - used during the restoration period
Sword - Nobility
Tree - Liberty
Triangle - The perfect accord
Two enlaced 'L's - Emblem of the Monarchy
Young woman with mirror - Truth

One of the main contributions of the French Revolution was the adoption of the metric system. An attempt to decimalize all aspects of daily life (calendar, measurements, currency, etc.)

As elsewhere in Europe, France’s old weights and measures originated from a system used by the Romans, which had evolved into a multitude of local variations. Enlightenment scholars were faced with the task of reforming a jumble of 800 different units of measurement, ranging from the toise to the lieue, including the quart and the pinte.

Some of these units were quite extravagant: in early 18th-century Bordeaux, a unit of land was defined by the distance a man’s voice could carry! It was better to have a loud voice if you wanted to be a landowner.

There was little to no standardization: in Paris, for example, a pinte equaled 0.93 liters, while in Saint-Denis it was 1.46 liters. An aune, used to measure fabric, was based on the width of local looms and varied greatly. This chaotic system was prone to fraud and stifled both domestic and international trade.

Courtesy: Jaz le Bon Temps

1793 Decimal or Revolutionary time was adopted by decree of the National Convention in 1793. (more on the adoption) It stipulated that the Gregorian calendar should be abandoned and replaced by the Republican calendar which divided the day into ten hours each with one hundred minutes and then further sub-divided into one hundred seconds.
Although perhaps a logical 'simplification' of timekeeping the habits of the populous were difficult to change. The new system meant having to design a new dial and to this end a competition was organized to invent one that was clear and easy to read.

1795 Despite the efforts of some of the great horological minds the system was never really adopted and clockmakers had no real reason to fully support it because their Revolution clocks and watches were useless outside France which ruined their export trade.

By art. 22, April 7, 1795 it was no longer compulsory to use Decimal time and even before then clocks and watches were being made with both the 'old' and 'new' time displays as on the hybrid example below.

1806 Finally it was decreed that the Decimal system had proved impossible to implement properly and from January 1, 1806 French timekeeping reverted back to the traditional system.

(click to enlarge)

  CALENDAR & TIME

The republican year commences the 22nd of september and ends the 21st of september.

The years were numbered as follows:

The year is divided in 12 equal months of 30 days each, plus 5 or 6 days called 'sans-culottides' (the days of the poor) which were renamed, after august 24 1794, 'complementary days'. (jours complémentaires)  

They were treated as Holidays, or Festival days and were named:

       The names of the months are:

Each month was divided in three equal parts of 10 days named:

The names of the days of the decades were:
 

Each day was divided in: 

  10 hours of 100 minutes of 100 seconds each.

A multiple of ten decimal minutes was often called a 'décime', i.e. one-tenth of a decimal hour. It was also conveniently close to a traditional quarter-hour.

Museo Galileo Galilei. British museum. Stephen Bogoff. Kerkhoff antiques. CNAM, Paris musees. La Pendulerie. Redding antiques. Yves Droz. Joseph Flores. Ton Bollen. Christies. Patek Philippe museum.

1) Les Heures Revolutionnaires.
Yves Droz et Joseph Flores
Edité par l'Afaha.
 

2) Cadrans de la Révolution, 1789-1800
Watch dials of the French Revolution,
Zifferblätter der französischen Revolution,
Roberto Panicali.
Publisher: Scriptar Lausanne 1972
ISBN: B0000E810O

3) Decimal time history.
by: John D. Hynes.

4) More on the ADOPTION of the new calendar.
 
As to the New Calendar, we may say here rather than elsewhere that speculative men have long been struck with the inequalities and incongruities of the Old Calendar; that a New one has long been as good as determined on. Marechal the Atheist, almost ten years ago, proposed a New Calendar, free at least from superstition: this the Paris Municipality would now adopt, in defect of a better; at all events, let us have either this of Marechal`s or a better,--the New Era being come. Petitions, more than once, have been sent to that effect; and indeed, for a year past, all Public Bodies, Journalists, and Patriots in general, have dated First Year of the Republic. It is a subject not without difficulties. But the Convention has taken it up; and Romme<sup>2</sup> , as we say, has been meditating it; not Marechal`s New Calendar, but a better New one of Romme`s and our own. Romme, aided by a Monge, a Lagrange and others, furnishes mathematics; Fabre d`Eglantine furnishes poetic nomenclature: and so, on the 5th of October 1793, after trouble enough, they bring forth this New Republican Calendar of theirs, in a complete state; and by Law, get it put in action.

(back to context)

Source: The French Revolution A History.
By Thomas Carlyle.

5) Why the adoption was doomed to fail.

...The fact was, hardly anybody in France wanted decimal time. Most people owned a clock or watch simply to find the time of day, whether they read it from a dial or heard it from the chiming of a bell. They did not use timepieces to make mathematical calculations. Such lofty practices were the preserve of astronomers and physicists. And these
specialists hardly constituted a mass market. Whatever the politics of decimal time, it was economics that caused its apparent downfall....

Ref: Anthony Turner. Drawn from his chapter “Decimal Time,” in A General History of Horology, ed. Turner, Nye, and Betts, Oxford University Press (2022)
 

1) Chapters.

In a horological context, a chapter is the scale of divisions and markings -such as numbers or signs- used to read the time and related indications on a dial. These markings may be engraved, painted, printed or otherwise applied, either directly onto the dial or on attached elements such as 'cartouches' or a 'chapter ring'.

2) Charles-Gilbert Romme (1750–1795)

A French revolutionary and mathematician, famous for creating the French Republican Calendar and the adoption of the metric system. Was sentenced to death as a Follower of the failed Prairial uprising of 1 Prairial An III May 1795. He committed suicide by stabbing himself to avoid the guillotine, and became known as one of the Martyrs of Prairial.