French Republic years :

Beginning 22 Sept. 1792, day 1 of the First Republic, France instituted a new calendar which continued for the next 14 years. A year consists of 365 or 366 days, divided into 12 months of 30 days each, followed by 5 or 6 additional days.

An 1 1792-1793
An 2 1793-1794
An 3 1794-1795
An 4 1795-1796
An 5 1796-1797
An 6 1797-1798
An 7 1798-1799
An 8 1799-1800
An 9 1800-1801
An 10 1801-1802
An 11 1802-1803
An 12 1803-1804
An 13 1804-1805
An 14 22 Sept. - 22 Dec. 1805

The months were:

1. Vendémiaire
2. Brumaire
3. Frimaire
4. Nivôse
5. Pluviôse
6. Ventôse
7. Germinal
8. Floréal
9. Prairial
10. Messidor
11. Thermidor
12. Fructidor