Why is the date format different for the same culture on different computers or OS?

Question

I have problem with date formate while hosting site which is developed using C# .net MVC .

In my development machine(OS:Windows 7, .net Framework 4.5) date formate for Spanish-Panama(es-PA) is mm/dd/yy and in server machine(OS:Windows 8, .net Framework 4.5) it is giving d/m/yy format for same culture.

I checked it with by using simple console application.

public static void Main()
{
    DateTime dt = DateTime.Now;
    Thread.CurrentThread.CurrentCulture = new CultureInfo("es-PA");

    Console.WriteLine(dt.ToString("d"));

    Console.ReadLine();
}

Output on development machine is: 10/08/2015

Output on server machine is : 8/10/15

I also checked by changing Language and Regional but in both machine default format is different.

Why format is different in different machine for same culture? Is there any solution for this?

Optative

Probably because on a server the default is not meant for an "average" user. – Lasting

Answer 1

Why format is different in different machine for same culture?

Because formats are updated over time, in different OS releases and in patches/hotfixes. .NET is fetching the format from the OS (I believe, anyway), so it's the OS that's the source of the difference - as you've seen in the regional settings.

Is there any solution for this?

Check that both machines are up to date with Windows Update, and possibly check for any hotfixes available for this. Otherwise, you could always manually update the one you want to change, but obviously that's far from ideal.

It's possible that Windows 8 just has more up-to-date information than Windows 7 in a way that isn't going to be addressed by Windows update :(

Farseeing

Can we have sources demonstrating this? – Offal

I encounter the issue right now on one Windows machine that has an incorrect decimal separator for the fr-FR culture. I cannot find a "windows changelog" where culture updates are listed. This would help a lot. Is Microsoft documenting these changes?. (For my problem I believe it's not a culture update. Colleagues don't have the issue.) – Offal

@SandRock: It could be that the culture information has been manually modified on that machine via the Regional Settings control panel applet. I don't know of a changelog for this, I'm afraid. – Farseeing

Answer 2

Cultures have multiple accepted formats. The thread gets it culture (and thus format) from the account the thread is executing as.

For example if you are running IIS express on your dev machine (IIS express uses the windows users account for ASP.NET worker process) you can change to another valid format, for that same culture in windows and this would now be the outputed format for your web application.

It is hard to give a solution for a non issue. It is still the same date, and actually displays the set culture properly.

However if you want to force a format, you should be able to do that by setting for example CurrentCulture.DateTimeFormat.ShortDatePattern

Nathanialnathaniel

No, this isn't the problem. The problem is that the same culture is associated with different formats on different machines. – Farseeing

Then you've made your point very confusingly. It's entirely reasonable to expect the same culture to mean the same thing on multiple versions of an operating system, unless it's been manually tweaked. That appears not to be the case here, but you haven't explained it at all. You claim it's a non-issue, but it definitely sounds like an issue to me. Suppose you have a web app spread across multiple machines, and they take the desired culture ID from the request... wouldn't it be weird for the user to see different results depending on the machine it hit? – Farseeing

I might not be very good at explaining, not even in my native tongue. I Apologize for that. I think you are right that .NET fetches the format from the OS. I have seen people get different date formats running the same code, despite using the same OS culture. Only difference being they had different date formats set for that culture on the OS (Windows 10 machines). So my thought was, even if they would have same default date format in this case. There is always a risk that the format will differ if OS settings change, and you can't expect the code to return the same format always. – Nathanialnathaniel

Saw you edit after my post. It would absolutely be a problem. When I have worked on projects like that we have solved it by having a culture setting on users so they always get what they want. Fallback to company default when not chosen. Saying it is a non issue, was wrong on my part. Meant you get expected format from OS. – Nathanialnathaniel