Stephen P. Morse , San Francisco

**Hours, Minutes, Seconds**

Day is divided into 10 hours

Each hour is divided into 100 minutes

Each minute is divided into 100 seconds

Therefore 1 french second = 60*60*24/100*100*10 = 0.864 regular seconds

**Years, Months, Days**

Year is divided into 12 months

Each month is divided into 3 decades of 10 days each

The 12 months are followed by 5 additional days (6 additional days
in leap year)

*Leap Year Rules*

The calendar specifies that years 3, 7, 11, and 15 are to be leap years

Beyond that it is unclear what was supposed to happen, and the calendar was abandoned in French year 12
so it never became an issue

There are several theories as to what was supposed to happen. They are:

1. Straight 4-year Rule: The leap years are all French years preceding a French year divisible by 4. So the initial leap years are 3, 7, 11, 15, 19, 23, etc.

2. 4/100/400-year Rule: The leap years are French years 3, 7, 11, 15, 20, and every four years thereafter except if the French year is divisible by 100 it must also be divisible by 400 to be a leap year.

3. 4/128-year Rule: The leap years are French years 3, 7, 11, 15, 20, and every four years thereafter except if the French year is divisible by 128 it is not a leap year.

*Names of Months*

1. Vendémiaire (vintage)

2. Brumaire (mist)

3. Frimaire (frost)

4. Nivôse (snow)

5. Pluviôse (rain)

6. Ventôse (wind)

7. Germinal (seed-time)

8. Floréal (blossom)

9. Prairial (meadow)

10. Messidor (harvest)

11. Thermidor (heat)

12. Fructidor (fruit)

*Names of the Additional Days*

1. Fete de la vertu (Celebration of virtue)

2. Fete du genie (Celebration of genius)

3. Fete du travail (Celebration of labor)

4. Fete de l'opinion (Celebration of opinion)

5. Fete des recompenses (Celebration of rewards)

6. Jour de la revolution (Day of the revolution) (the leap day )

*Names of the Days in each Decade*

1. Primidi

2. Duodi

3. Tridi

4. Quartidi

5. Quintidi

6. Sextidi

7. Septidi

8. Octidi

9. Nonidi

10. Decadi

**Origin**

1 Vendémiaire in year 1 = September 22, 1792 (Gregorian)