Question

I am trying to localize A.M. & P.M. in datetime in C#.

How reliable is it to use values returned by C#’s ‘PMDesignator’ & ‘AMDesignator’ (as in the code below) ?

How can I handle both the below scenarios using the same code?

                                                                        //Line# Output
                                                                        //----- ------
void Main()                                                             //1
{                                                                       //2
    DateTime dt = DateTime.Now; // it is 5:56 PM now                    //3 it is 5:56 PM now   
                                                                        //4
    //Japanese                                                          //5
    var JapaneseCulture = new System.Globalization.CultureInfo("ja");   //6 
    Console.WriteLine(JapaneseCulture.DateTimeFormat.PMDesignator);     //7     午後
    Console.WriteLine(JapaneseCulture.DateTimeFormat.AMDesignator);     //8     午前
    Console.WriteLine(dt.ToString("t",JapaneseCulture));                //9     17:56
    Console.WriteLine(dt.ToString("hh:mm tt",JapaneseCulture));         //10    05:56 午後
                                                                        //11
    //German                                                            //12
    var GermanCulture = new System.Globalization.CultureInfo("de");     //13    
    Console.WriteLine(GermanCulture.DateTimeFormat.PMDesignator);       //14    (blank)
    Console.WriteLine(GermanCulture.DateTimeFormat.AMDesignator);       //15    (blank)
    Console.WriteLine(dt.ToString("t",GermanCulture));                  //16    17:56
    Console.WriteLine(dt.ToString("hh:mm tt",GermanCulture));           //17    05:56
}

Japanese –
PMDesignator, AMDesignator have values,
but are not shown in Line 9 when using “t”.
In this case the format specified in Line 10 (“hh:mm tt”) gives more correct output.

German –
PMDesignator, AMDesignator don’t have values,
so using “t” as in Line 16 gives the correct output,
while Line 17 which uses “hh:mm tt” gives incorrect output.

[EDIT: After reading comments:]
Does “t” give the “typically” used formats fairly reliably? (I have no prior experience in localization, so I do not have a good idea of how reliable the values are)

Answer 1

The Standard Date and Time Format Strings in .NET will do the correct thing for the user’s culture. In your case just use:

var culture = new CultureInfo("ja");
var dt = DateTime.Now;
Console.WriteLine(dt.ToString("t", culture)); // t => Short Time format.

Only override the culture-specific format with customizations if really required by a specific business requirement.

Microsoft throws a lot of money at their localization efforts to ensure that formatting, translations, etc. are correct for everyone.