To establish a new Republican identity, French revolutionaries replaced monarchical and religious symbols with 'enlightenment' imagery and introduced a decimal based calender (1793–1806).
Revolution clock dials divided the day into 10 hours of 100 minutes, aligning timekeeping with the decimal system.

Although perhaps a logical 'simplification' of timekeeping the habits of the populous were difficult to change 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.
 

To ensure marketability, horologists typically integrated traditional chapters alongside decimal ones. This hybrid design of revolutionary dials reflects the socio-cultural resistance to time decimalization.

Consequently, surviving timepieces with purely decimal faces are now quite rare.
 

(click to enlarge)

 Hybrid dials featuring combined
traditional & decimal chapters¹

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.)

Standardization was badly needed since France’s Roman-derived measurement system had fractured into roughly 800 local variants. Standards were inconsistent and often arbitrary. A pinte in Paris differed from one in Saint-Denis, and some land was measured by the reach of a man’s voice. This chaos facilitated fraud and stifled trade home and abroad.

Unlike Republican time and calendar reform, the metric system endured and eventually -under Napoleon- spread across several other European countries.

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 and decimal time (more on the calendar)  

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 Gregorian 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.

  SOME REVOLUTIONARY 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. 

The 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.

 Revolution, Liberty and the struggle against oppression.

The Cockade (Cocarde tricolore) is a powerful republican symbol and the origin of the national flag. It's a circular ornament made of pleated ribbons in the national colors: blue in the center, white in the middle, and red on the outer edge.

In 1792, it became the official symbol of the Revolution and was famously worn on Phrygian  caps (liberty caps) by the Sans-culottes.

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

Revolutionary power. Vigilance and readiness to fight for revolutionary ideals.

A peoples weapon, famously used during the Storming of the Bastille to break the ultimate symbol of royal tyranny.

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.

Equalty and justice

The scales highlighted the shift from arbitrary royal justice to a new, egalitarian legal system. The scale was an attribute of the Roman Goddess Justitia.

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 magistrates with imperium -consuls, praetors, and dictators- who could command and read the gods’ will from 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: monarchical sunburst in stead of a cockerel.

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, Divine knowledge
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

 

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

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)

Gilbert Romme was a prominent French revolutionary and mathematician best known for designing the French Republican Calendar. As a leading member of the commission tasked with standardizing weights and measures, he played a critical role in the development of the metric system.  After the failed uprising of 1 Prairial An III -May 1795- Romme was sentenced to death as a loyal follower of the Montagnard faction. To avoid the guillotine, he committed suicide when being led away from the courtroom. Cementing his legacy as one of the Martyrs of Prairial.