using System;

​

using System.Text.Json;

using System.Text.Json.Serialization;

​

public class Program

{

    public class DateTimeConverter : JsonConverter<DateTime>

    {

        public override DateTime Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)

        {

            return DateTime.Parse(reader.GetString());

        }

​

        public override void Write(Utf8JsonWriter writer, DateTime value, JsonSerializerOptions options)

        {

             writer.WriteStringValue(value.ToString());

        }

    }

​

    public static void Main()

    {

        var options = new JsonSerializerOptions();

​

        options.Converters.Add(new DateTimeConverter());

​

        var xxx = "\"2019-12-19T02:34:20.000+0000\"";

​

        var ob = JsonSerializer.Deserialize<DateTime>(xxx, options);

​

        Console.WriteLine(ob.ToString());

    }

}