LinkeEngineering.CalendrierRepublicain 1.2.0

Calendrier Republicain

A .NET 8 library for converting and formatting dates between the Gregorian and French Republican calendars. It provides a drop-in replacement for the standard calendar and formatting infrastructure, enabling seamless integration in .NET applications.

The library is published as a NuGet package and designed for use in other .NET projects.

Usage

Restrictions

The library strictly implements the official features of the French Republican calendar, valid only between 1 Vendémiaire I (September 22, 1792) and 10 Nivôse XIV (December 31, 1805).
Dates outside this range and decimal time are not supported.

Creating Republican Dates

You can instantiate a DateTime object using the FrenchRepublicanCalendar class, which derives from System.Globalization.Calendar. This allows you to work with French Republican dates in all standard .NET APIs that support custom calendars.

using LinkeEngineering.CalendrierRepublicain;

var repCalendar = new FrenchRepublicanCalendar();
var date = new DateTime(8, 2, 18, repCalendar);

Console.WriteLine(date.ToString("d", DateTimeFormatInfo.InvariantInfo));
// Output: 11/9/1799

Writing Dates

You can format French Republican dates using the FrenchRepublicanDateTimeFormatter as a format provider with String.Format. This enables custom and standard date patterns for output in the Republican calendar.

using LinkeEngineering.CalendrierRepublicain;

var formatter = new FrenchRepublicanDateTimeFormatter();
var date = new DateTime(8, 2, 18, repCalendar);

Console.WriteLine(String.Format(formatter, "{0:D}", date));
// Output: Octidi, Brumaire 18, VIII

Console.WriteLine(String.Format(formatter, "{0:d MMM. 'an' yyyy}", date));
// Output: 18 Brum. an VIII

Supported patterns:

• "D": Long date format (Republican day name, month name, day, year in Roman numerals)
• "d": Short date format (day, abbreviated month, year)
• Custom patterns using:
  • d (day number)
  • dddd (Republican day name)
  • MMM/MMMM (abbreviated/full month name)
  • yyyy (year in Roman numerals)
  • H/HH (hour)
  • mm (minute)
  • ss (second)

Remarks:

• Only dates created with FrenchRepublicanCalendar are supported.
• Formatting outside the supported date range will throw an exception.
• Not all .NET date/time patterns are supported; use only the patterns listed above.

Working with the Calendar

The FrenchRepublicanCalendar class derives from System.Globalization.Calendar and provides all standard calendar operations for the French Republican calendar. You can add days, weeks, months, or years, and retrieve calendar-specific information.

using LinkeEngineering.CalendrierRepublicain;

var calendar = new FrenchRepublicanCalendar();
var formatter = new FrenchRepublicanDateTimeFormatter();

var date = new DateTime(8, 2, 18, calendar);  // 18 Brumaire VIII

// Add 4 Republican weeks (40 days)
date = calendar.AddWeeks(date, 4);
Console.WriteLine(String.Format(formatter, "{0:d MMMM yyyy}", date));
// Output: 28 Frimaire VIII

// Get the Republican year and month
var year = calendar.GetYear(date);   // 8
var month = calendar.GetMonth(date); // 3 (Frimaire)

License

This library is licensed under the MIT License, with additional terms restricting the use of the original package name for modified versions. Please refer to the license file for details.