French Republican Calendar Converter

Convert dates between the Gregorian calendar and the French Republican Calendar used during the Revolution (1792–1805). Choose your conversion direction, then enter either a Gregorian date or a Republican day, month, and year. You get back the full converted date, the Republican month name, the décade day name, and the dedicated plant or object name for that day — a fascinating window into Revolutionary France.

Enter a date between 22 Sep 1792 and 31 Dec 1805 for best results.

Enter a day from 1 to 30 (or 1–5 for complementary days).

Year I started 22 Sep 1792. Year XIV ended 31 Dec 1805.

Results

Converted Date

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Republican Date (Full)

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Gregorian Date (Full)

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Décade Day Name

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Day Dedication

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Republican Year (Roman)

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Frequently Asked Questions

What is the French Republican Calendar?

The French Republican Calendar (also called the French Revolutionary Calendar) was created during the French Revolution to replace the Gregorian calendar. Officially in use from 15 Vendémiaire Year II (6 October 1793) to 10 Nivôse Year XIV (31 December 1805), it was designed to de-Christianize French society and introduce a more rational, nature-based timekeeping system.

How does the French Republican Calendar work?

The calendar consists of 12 months of exactly 30 days each, divided into three 10-day weeks called décades. The year ends with 5 or 6 complementary days (Jours Complémentaires). The year begins on the day of the autumnal equinox as observed at the Paris Observatory, meaning the calendar never drifts relative to the seasons.

What are the names of the Republican months?

The 12 months are: Vendémiaire (Vintage), Brumaire (Mist), Frimaire (Frost), Nivôse (Snow), Pluviôse (Rain), Ventôse (Wind), Germinal (Seedtime), Floréal (Blossom), Prairial (Meadow), Messidor (Harvest), Thermidor (Heat), and Fructidor (Fruit). The names were invented by the poet Fabre d'Églantine to reflect the natural seasons.

What are décade day names?

Instead of a seven-day week, the Republican calendar used a 10-day cycle called a décade. The days were named Primidi (1st), Duodi (2nd), Tridi (3rd), Quartidi (4th), Quintidi (5th), Sextidi (6th), Septidi (7th), Octidi (8th), Nonidi (9th), and Décadi (10th). Décadi replaced Sunday as the rest day.

What is a 'day dedication' in the Republican Calendar?

Each of the 360 days in the 12 regular months was dedicated to a plant, animal, tool, or mineral instead of a Christian saint. For example, day 1 of Vendémiaire is dedicated to the grape (raisin). These dedications were part of the effort to replace religious symbolism with natural and agricultural imagery.

When was the French Republican Calendar used?

The calendar was officially decreed on 5 October 1793 (14 Vendémiaire Year II) and retroactively set to begin on 22 September 1792 (Year I). It was abolished by Napoleon under an imperial sénatus-consulte issued on 22 Fructidor Year XIII (9 September 1805), with the Gregorian calendar restored from 1 January 1806.

How are Republican years written?

Republican years are written in Roman numerals, from Year I (1792–93) through Year XIV (1805–06). Because the year starts at the autumnal equinox (around 22 September), each Republican year overlaps two Gregorian years. For example, Year II ran from 22 September 1793 to 21 September 1794.

What date range does this converter support?

This converter supports dates from 1 Vendémiaire Year I (22 September 1792), the founding of the French First Republic, through the end of Year XIV (31 December 1805), the last official day of the Republican Calendar. Dates outside this range may not convert accurately.

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