Deerialize utc-time different from the original field utc-time

[hxmcn]

For a simple Object with DateTime field, assign UTC-Time to it and serialize the object to json-text, then deserialize an object from the same json-text, the UTC-Time does not match with the original value (your time zone should not be UTC to reproduce the bug).

Code Example:

public class MUtcTime
{
public long ID { get; set; }
public DateTime LogUtcTime { get; set; }
}

    public static void Test()
    {
        var m = new MUtcTime
        {
            ID = 100,
            LogUtcTime = DateTime.UtcNow,
        };

        var jText = fastJSON.JSON.ToJSON(m);
        var gBack = fastJSON.JSON.ToObject<MUtcTime>(jText);
        if (m.LogUtcTime == gBack.LogUtcTime)
            Console.Write("Pass");
        else
            Console.Write("Failed");
    }

[mgholam]

Is the year, month, day...seconds the same?

[hxmcn]

Yes. but the hour is different.

[mgholam]

If you add the following:

        Console.WriteLine(m.LogUtcTime);
        Console.WriteLine(gBack.LogUtcTime);

You will get :

2021-12-26 15:42:12
2021-12-26 15:42:12

Which shows the dates are the same, however the objects will not be since the nano seconds are not set on the deserialized dates, hence your condition will fail.

[hxmcn]

Sorry, I got different result:
Source:2021-12-28 23:19:58
GetBack:2021-12-29 07:19:58

Please see the picture below for details:

---

Environment:
Windows 10 English (Time zone is UTC+8, Beijing time)
Visual Studio 2022 Community
.Net 6 Console Application with fastJSON 2.4.0.4 installed from Nuget:
PackageReference Include="fastJSON" Version="2.4.0.4"

---

Full source code:
namespace TestCode
{
public class TestClass
{
public class Model { public long ID { get; set; } public DateTime UtcTime { get; set; } }

    public static int Main()
    {
        // See https://aka.ms/new-console-template for more information
        Console.WriteLine("Hello, World!");

        var model = new Model { ID = 100, UtcTime = DateTime.UtcNow };
        var jsonText = fastJSON.JSON.ToJSON(model);
        var gBack = fastJSON.JSON.ToObject<Model>(jsonText);

        Console.WriteLine("Source:" + model.UtcTime.ToString("yyyy-MM-dd HH:mm:ss"));
        Console.WriteLine($"JsonText: {jsonText}");
        Console.WriteLine("GetBack:" + gBack.UtcTime.ToString("yyyy-MM-dd HH:mm:ss"));

        return 0;
    }
}

}

[mgholam]

My results

***** tests.aaaaaaa
Source:2021-12-29 06:15:41
JsonText: {"$types":{"tests+Model, UnitTests, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null":"1"},"$type":"1","ID":100,"UtcTime":"2021-12-29T06:15:41Z"}
GetBack:2021-12-29 06:15:41

[mgholam]

Try testing @12:00 noon

[mgholam]

also

        var jsonText = fastJSON.JSON.ToJSON(model, new JSONParameters { UseUTCDateTime =true});
        var gBack = fastJSON.JSON.ToObject<Model>(jsonText , new JSONParameters {  UseUTCDateTime=true});

[hxmcn]

Thanks @mgholam
However, my test shows set UseUTCDateTime = false is OK:

---

Full source codes:
using fastJSON;

namespace TestCode
{
public class TestClass
{
public class Model { public long ID { get; set; } public DateTime UtcTime { get; set; } }

    public static int Main()
    {
        void Test(string notes, JSONParameters? jParams = null)
        {
            var model = new Model { ID = 100, UtcTime = DateTime.UtcNow };

            var jsonText = jParams == null ? JSON.ToJSON(model) : JSON.ToJSON(model, jParams);
            var gBack = jParams == null ? JSON.ToObject<Model>(jsonText) : JSON.ToObject<Model>(jsonText, jParams);

            Console.WriteLine(notes);
            Console.WriteLine($"\tSource:{model.UtcTime}");
            Console.WriteLine($"\tJsonText: {jsonText}");
            Console.WriteLine($"\tGetBack:{gBack.UtcTime}{Environment.NewLine}");
        }

        Test("Without JSONParameters:");
        Test("UseUTCDateTime = true:", new JSONParameters { UseUTCDateTime = true });
        Test("UseUTCDateTime = false:", new JSONParameters { UseUTCDateTime = false });

        Console.Read();
        return 0;
    }
}

}