INotableDateAlgorithm Interface

Definition

Namespace: Bodu.Globalization.Calendar.Algorithms

Assembly: Bodu.Globalization.Calendar.dll

Package: Bodu.Globalization.Calendar 1.0.1

Source: INotableDateAlgorithm.cs

Computes the date of a notable date for a Gregorian year from a closed-form or tabular algorithm. Implementations are registered under a key and dispatched by the AlgorithmDateStrategy when a rule references that key, allowing the algorithm catalogue to be extended beyond the built-in computations.

public interface INotableDateAlgorithm

Extension Methods: ComparableExtensions.AtLeast<T>(T, T, IComparer<T>)

ComparableExtensions.AtMost<T>(T, T, IComparer<T>)

ComparableExtensions.IsEqualTo<T>(T, T, IComparer<T>)

ComparableExtensions.Max<T>(T, T, IComparer<T>)

ComparableExtensions.Min<T>(T, T, IComparer<T>)

Examples

// A custom algorithm returning the March equinox (UTC) for the supplied year.
public sealed class MarchEquinoxAlgorithm : INotableDateAlgorithm
{
    public DateOnly? Calculate(int year) =>
        year is >= 1900 and <= 2100
            ? DateOnly.FromDateTime(AstronomyTables.MarchEquinox(year))
            : null; // unsupported year: return null rather than throw
}

Remarks

Implementations must be deterministic, side-effect-free, and thread-safe, and should return null for a year outside their supported range rather than throwing.

When to implement. Provide a custom algorithm when a notable date follows a computation the built-in strategies do not cover - for example an astronomical event or a bespoke ecclesiastical rule. Register the implementation under a key in an INotableDateAlgorithmRegistry, pass that registry to the loader and the NotableDateService, and reference the key from a rule's algorithm strategy.

Methods

Calculate(int)

Calculates the occurrence for the supplied Gregorian year.

DateOnly? Calculate(int year)

Parameters

year int: The Gregorian year to calculate against.

Returns

DateOnly?: The occurrence date, or null when the year is unsupported.

Applies to

Product	Versions
.NET	8, 10

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