French revolution
decimal time.

October 5th 1793, adoption.

April 7th 1795, no longer obligatory.
1st of January 1806, use practically ends.
Republican           Gregorian
Vendémaire 1 I 22 Sept. 1792
Brumaire 2 22 October
Frimaire 3 21 November
Nivôse 4 21 December
Pluviôse   1793 20 January
Ventôse 6 19 February
Germinal 7 21 March
Floréal 8 20 April
Prairial 9 20 May
Messidor 10 19 June
Thermidor 11 19 July
Fructidor 12 18 August
Vendémaire 1 II 22 September
Brumaire 2 22 October
Frimaire 3 22 November
Nivôse 4 21 December
Pluviôse 5 1794 20 January
Ventôse 6 19 February
Germinal 7 21 March
Floréal 8 20 April
Prairial 9 20 May
Messidor 10 19 June
Thermidor 11 19 July
Fructidor 12 18 August
Vendémaire 1 III 22 September
Brumaire 2 22 October
Frimaire 3 22 November
Nivôse 4 21 December
Pluviôse 5 1795 20 January
Ventôse 6 19 February
Germinal 7 21 March
Floréal 8 20 April
Prairial 9 20 May
Messidor 10 19 June
Thermidor 11 19 July
Fructidor 12 18 August
Vendémaire 1 IV 23 September
Brumaire 2 23 October
Frimaire 3 22 November
Nivôse 4 22 December
Pluviôse 5 1796 21 January
Ventôse 6 20 February
Germinal 7 21 March
Floréal 8 20 April
Prairial 9 20 May
Messidor 10 19 June
Thermidor 11 19 July
Fructidor 12 18 August
Vendémaire 1 V 22 September
Brumaire 2 22 October
Frimaire 3 22 November
Nivôse 4 21 December
Pluviôse 5 1797  20 January
Ventôse 6 19 February
Germinal 7 21 March
Floréal 8 20 April
Prairial 9 20 May
Messidor 10 19 June
Thermidor 11 19 July
Fructidor 12 18 August
Vendémaire 1 VI 22 September
Brumaire 2 22 October
Frimaire 3 22 November
Nivôse 4 21 December
Pluviôse 5 1798 20 January
Ventôse 6 19 February
Germinal 7 21 March
Floréal 8 20 April
Prairial 9 20 May
Messidor 10 19 June
Thermidor 11 19 July
Fructidor 12 18 August
Vendémaire 1 VII 22 September
Brumaire 2 22 October
Frimaire 3 22 November
Nivôse 4 21 December
Pluviôse 5 1799 20 January
Ventôse 6 19 February
Germinal 7 21 March
Floréal 8 20 April
Prairial 9 20 May
Messidor 10 19 June
Thermidor 11 19 July
Fructidor 12 18 August
Vendémaire 1 VIII 23 September
Brumaire 2 23 October
Frimaire 3 22 November
Nivôse 4 22 December
Pluviôse 5 1800 21 January
Ventôse 6 20 February
Germinal 7 22 March
Floréal 8 21 April
Prairial 9 21 May
Messidor 10 20 June
Thermidor 11 20 July
Fructidor 12 19 August
Vendémaire 1 IX 23 September
Brumaire 2 23 October
Frimaire 3 22 November
Nivôse 4 22 December
Pluviôse 5 1801 21 January
Ventôse 6 20 February
Germinal 7 22 March
Floréal 8 21 April
Prairial 9 21 May
Messidor 10 20 June
Thermidor 11 20 July
Fructidor 12 19 August
Vendémaire 1 X 23 September
Brumaire 2 23 October
Frimaire 3 22 November
Nivôse 4 22 December
Pluviôse 5 1802 21 January
Ventôse 6 20 February
Germinal 7 22 March
Floréal 8 21 April
Prairial 9 21 May
Messidor 10 20 June
Thermidor 11 20 July
Fructidor 12 19 August
Vendémaire 1 XI 23 September
Brumaire 2 23 October
Frimaire 3 22 November
Nivôse 4 22 December
Pluviôse 5 1803 21 January
Ventôse 6 20 February
Germinal 7 22 March
Floréal 8 21 April
Prairial 9 21 May
Messidor 10 20 June
Thermidor 11 20 July
Fructidor 12 19 August
Vendémaire 1 XII 24 September
Brumaire 2 24 October
Frimaire 3 23 November
Nivôse 4 23 December
Pluviôse 5 1804 22 January
Ventôse 6 21 February
Germinal 7 22 March
Floréal 8 21 April
Prairial 9 21 May
Messidor 10 20 June
Thermidor 11 20 July
Fructidor 12 19 August
Vendémaire 1 XIII 23 September
Brumaire 2 23 October
Frimaire 3 22 November
Nivôse 4 22 December

Pluviôse 5 1805 21 January
Ventôse 6 20 February
Germinal 7 22 March
Floréal 8 21 April
Prairial 9 21 May
Messidor 10 20 June
Thermidor 11 20 July
Fructidor 12 19 August
Vendémaire 1 XIV 23 September
Brumaire 2 23 October
Frimaire 3 22 November
Nivôse 4 22 December
Pluviôse 5 1806 21 January
Ventôse 6 20 February
Germinal 7 22 March
Floréal 8 21 April
Prairial 9 21 May
Messidor 10 20 June
Thermidor 11 20 July
Fructidor 12 19 August
Vendémaire 1 XV 23 September
Brumaire 2 22 October
Frimaire 3 22 November
Nivôse 4 21 December
Pluviôse 5 1807 20 January
Ventôse 6 22 February
Germinal 7 21 March
Floréal 8 21 April
Prairial 9 20 May
Messidor 10 20 June
Thermidor 11 19 July
Fructidor 12 23 August
Vendémaire 1 XVI 23 September
Brumaire 2 22 October
Frimaire 3 22 November
Nivôse 4 21 December