using System;

using NodaTime;

using NodaTime.Serialization.SystemTextJson;

using NodaTime.Text;

using System.Collections.Generic;

using System.Text.Json;

using System.Text.Json.Serialization;

​

public static class Test

{

    public static void ConfigureJsonOptions(JsonSerializerOptions options)

        {

            options.PropertyNamingPolicy = JsonNamingPolicy.CamelCase;

            options.IgnoreNullValues = true;

            options.ConfigureForNodaTime(DateTimeZoneProviders.Tzdb);

            ReplaceExistingConverters<Instant>(converters: options.Converters,

                newConverter: new NodaPatternConverter<Instant>(InstantPattern.ExtendedIso));

        }

​

        private static void ReplaceExistingConverters<T>(

            IList<JsonConverter> converters,

            JsonConverter newConverter)

        {

            int index = converters.Count - 1;

            while (index >= 0)

            {

                if (converters[index].CanConvert(typeof(T)))

                {

                    converters.RemoveAt(index);

                }

​

                --index;

            }

​

            converters.Add(newConverter);

        }

}

​

public class Program

{

    public static void Main()

    { 

        var jsonSerializerOptions = new JsonSerializerOptions();

        jsonSerializerOptions.ConfigureForNodaTime(DateTimeZoneProviders.Tzdb);

        var instant1 = SystemClock.Instance.GetCurrentInstant();

        var instant2 = Instant.FromUnixTimeSeconds(instant1.ToUnixTimeSeconds());

        Console.WriteLine(instant1);

        Console.WriteLine(instant2);

        Test.ConfigureJsonOptions(jsonSerializerOptions);

        var x = new { Time1 = instant1, Time2 = instant2 };

        var result = System.Text.Json.JsonSerializer.Serialize(x, jsonSerializerOptions);

        Console.WriteLine(result);

    }

}