Globally overrride MonthNames for all instances of a specific culture

Question

So, i have this problem where Microsoft actually got the month names wrong for the Greenlandic culture (kl-GL). I also know that i can pass my own array of string to the DateTimeFormatInfo.MonthNames Property, but it seems like the values i specify is only used in the scope of that one CultureInfo instance. Is there a way to tell .Net that every time i have an instance of the kl-GL culture these specific monthnames should be used?

I know that you can create user specific cultures, but i don't have access to some legacy code to actually change the code to use a my own userspecified culture.

Answer 1

Why do you need more than one or two CultureInfo object? You can change the threading culture (System.Threading.Thread.CurrentThread.CurrentCulture) or the threading UI culture (System.Threading.Thread.CurrentThread.CurrentUICulture) to the values you need. Then you can use current culture or refer to the objects in CurrentThread if you need an explicit reference.

Answer 2

Here you go

    public static void RenameMonthNames(string cultureName, string[] newNames)
    {
        RenameMonthNames(cultureName, newNames, false);
        RenameMonthNames(cultureName, newNames, true);
    }


    public static void RenameMonthNames(string cultureName, string[] newNames, bool custom)
    {
        var nonPublicAndInstance = BindingFlags.NonPublic | BindingFlags.Instance;

        var culture = new CultureInfo(cultureName, custom);

        int calendarId = (int)typeof (System.Globalization.Calendar).GetProperty("ID", nonPublicAndInstance).GetValue(culture.Calendar, new object[0]);

        object cultureData = culture.GetType().GetField("m_cultureData", nonPublicAndInstance).GetValue(culture);

        cultureData.GetType().GetField("bUseOverrides", nonPublicAndInstance).SetValue(cultureData, false); // Magic hack!!!

        object calendarData = cultureData.GetType().GetMethod("GetCalendar", nonPublicAndInstance).Invoke(cultureData, new object[] { calendarId });

        calendarData.GetType().GetField("saMonthNames", nonPublicAndInstance).SetValue(calendarData, newNames);
        calendarData.GetType().GetField("saLeapYearMonthNames", nonPublicAndInstance).SetValue(calendarData, newNames);
        calendarData.GetType().GetField("saMonthGenitiveNames", nonPublicAndInstance).SetValue(calendarData, newNames);
    }

    public  void TestCultureInfoHack()
    {
        RenameMonthNames("da-DK", new string[]
                                      {
                                          "jan1", "feb2", "mar3", "apr", "may", "jun",
                                          "jul", "aug", "sep", "okt", "nov", "dec12", string.Empty
                                      });

        var today = DateTime.Now.ToLongDateString();
        Thread.CurrentThread.CurrentCulture = new CultureInfo("kl-gl", false);
        Response.Write(DateTime.Now.ToLongDateString());

        Response.Write("<br /> "); 

        Thread.CurrentThread.CurrentCulture = new CultureInfo("kl-GL");
        Response.Write(DateTime.Now.ToLongDateString());
        Response.Write("<br /> "); 
    }

NOTE: only for .NET 4.0

Answer 3

Replacing a specific culture.

var cultureBuilder = new CultureAndRegionInfoBuilder(
               "kl-GL", CultureAndRegionModifiers.Replacement);

cultureBuilder.LoadDataFromCultureInfo(new CultureInfo("kl-GL"));

cultureBuilder.GregorianDateTimeFormat.MonthNames = new []
                       {
                            "jan", "feb", "mar", "apr", "may", "jun",
                            "jul", "aug", "sep", "okt", "nov", "dec",
                            string.Empty    // needs to be here!!!
                       };

cultureBuilder.Register();

Don't execute this! It will overwrite your culture settings. Adjust as you need it.

Creating a new specific culture.

    static void Main(string[] args)
    {
        try
        {
           var builder = new CultureAndRegionInfoBuilder(
                "kl-GL-custom",
                CultureAndRegionModifiers.None);

            // bind the properties
            builder.LoadDataFromCultureInfo(new CultureInfo("kl-GL"));
            builder.LoadDataFromRegionInfo(new RegionInfo("kl-GL"));

            // make custom changes to the culture
            builder.GregorianDateTimeFormat.MonthNames = new []
                {
                    "jan", "feb", "mar", "apr", "may", "jun",
                    "jul", "aug", "sep", "okt", "nov", "dec",
                    string.Empty    // needs to be here!!!
                };

            // one time operation! needs admin rights!
            builder.Register();
        }
        catch
        {
        }

        Thread.CurrentThread.CurrentCulture = 
            Thread.CurrentThread.CurrentUICulture = 
                new CultureInfo("kl-GL-custom");

        Console.WriteLine(DateTime.Today.ToString("MMMM"));

    }

Using the new culture in ASP.NET is as trivial as adding this to your web.config:

<globalization culture="kl-GL-custom" uiCulture="kl-GL-custom"/>

or do this

    protected override void InitializeCulture()
    {
        Thread.CurrentThread.CurrentCulture = Thread.CurrentThread.CurrentUICulture = new CultureInfo("kl-GL-custom");

        base.InitializeCulture();
    }