using System;

using Newtonsoft.Json;

using Newtonsoft.Json.Linq;

using System.Linq;

​

public class Program

{

    public static void Main()

    {

        string json = @"{

                'x1': 1.55391E4,

                'x2': 2.2173244E5,

                'x3': 1.11226E3,

                 'UpdatedDateTime': '2023-01-17T20:45:51.959+08:00'

            }";

        JObject obj = JObject.Parse(json);

        JsonSerializerSettings settings = new JsonSerializerSettings()

        {FloatParseHandling = FloatParseHandling.Decimal, FloatFormatHandling = FloatFormatHandling.DefaultValue, DateParseHandling = DateParseHandling.DateTimeOffset, DateTimeZoneHandling = DateTimeZoneHandling.Unspecified};

        var obj2 = JsonConvert.DeserializeObject<JObject>(json, settings);

        Console.WriteLine(obj2); //preserveDateTimeZone

    }

}