LinkeEngineering.CalendrierRepublicain 2.0.1

Calendrier Républicain

A modern .NET 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 into .NET applications.

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

Installation

To install the library via NuGet, use the following command:

# Using the .NET CLI
> dotnet add package LinkeEngineering.CalendrierRepublicain --version 2.0.0

Alternatively, you can search for LinkeEngineering.CalendrierRepublicain in the NuGet Package Manager in Visual Studio.

Compatibility

This library targets .NET 8 and .NET 10. Ensure your project is compatible with one of these frameworks before integrating the library.

Dependencies

The library depends on the LinkeEngineering.NumeriRomani package (version 1.1.5) for handling Roman numeral formatting. This dependency is automatically resolved when you install the package.

Usage

Restrictions

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

Creating Republican Dates

You can create 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

Working with the Calendar

The FrenchRepublicanCalendar 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 repCalendar = new FrenchRepublicanCalendar();
var date = new DateTime(8, 2, 18, repCalendar);  // 18 Brumaire VIII

// Add 4 Republican weeks (40 days)
date = repCalendar.AddWeeks(date, 4);  // 28 Frimaire VIII

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

Formatting Dates

You can format French Republican dates using the FrenchRepublicanDateTimeFormatter as a format provider with String.Format. This enables both standard and custom date/time format strings for output in the Republican calendar. As with other .NET calendars, the culture determines the order of elements in standard format strings, while custom format strings allow you to specify the exact format.

using LinkeEngineering.CalendrierRepublicain;

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

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

Console.WriteLine(String.Format(repFormatter, "{0:dddd, dd MM yy}", date));
// Output: Octidi, 18 02 08

var complementaryDate = new DateTime(3, 13, 6, repCalendar);
Console.WriteLine(String.Format(repFormatter, "{0:dddd, dd MMMM 'an' yyyy}", complementaryDate));
// Output: Jour de la révolution an III

Remarks:

• Format strings that handle parts of seconds, time zones, or eras are not supported, as these concepts did not exist in the French Republican calendar. Using an unsupported standard format string like O results in a FormatException, while unsupported custom format strings like tt will be ignored in the output.
• The names of months and days are not translated, as they are specific to the calendar and do not have equivalents in other languages. They will always be displayed in their original French form, regardless of the culture used for formatting.
• The names of months and days are never abbreviated and are always displayed in their full form.
• Dates that fall in the complementary days (Sansculottides) will be formatted as a 13th month in numeric representation, and with the festival name in textual representation, e.g., 13/1/4 or Jour de la vertu, IV. There are no weekday names for these days.
• Time is always represented in 24-hour format, as the concept of AM/PM did not exist. Format specifiers for 12-hour time and AM/PM will be transformed to their 24-hour equivalents, e.g., h will be treated as H, and tt will be ignored.

Supported Standard Format Strings

Supported Custom Format Strings

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.