Develop Reference

How to create .NET CultureInfo with Dateformat ISO 8601?

Is it possible to make .NET create the following output?
DateTime.UtcNow.ToString() --> "2017-11-07T00:40:00.123456Z"
Of course there is always the possibility to use ToString("s") or ToString("yyyy-MM-ddTHH:mm:ss.fffffffK"). But is there a way to adjust the default-behaviour for the parameterless ToString-Method to the desired output?
I tried changing the CurrentCulture. But the best I got was "2017-11-07 00:40:00.123456Z". I did not find a way to change the separator between the date and the time from a space to "T".

It is possible, but only by accessing an internal field via reflection, which is not guaranteed to work in all cases.
var culture = (CultureInfo) CultureInfo.InvariantCulture.Clone();
var field = typeof(DateTimeFormatInfo).GetField("generalLongTimePattern",
BindingFlags.NonPublic | BindingFlags.Instance);
if (field != null)
{
// we found the internal field, set it
field.SetValue(culture.DateTimeFormat, "yyyy-MM-dd'T'HH:mm:ss.FFFFFFFK");
}
else
{
// fallback to setting the separate date and time patterns
culture.DateTimeFormat.ShortDatePattern = "yyyy-MM-dd";
culture.DateTimeFormat.LongTimePattern = "HH:mm:ss.FFFFFFFK";
}
CultureInfo.CurrentCulture = culture;
Console.WriteLine(DateTime.UtcNow); // "2017-11-07T00:53:36.6922843Z"
Note that the ISO 8601 spec does allow a space to be used instead of a T. It's just preferable to use the T.

Scott Hanselmann has blogged about it here.
a little Reflectoring shows us that the default format string for System.DateTime is "G" as in System.DateTime.ToString("G") where G is one of the presets.
[...]
And gets the output he expects, indicating that "G" is the combination of a ShortDate and a LongTime.
So you should override ShortDatePattern and LongTimePattern:
I converted the code to C# and yes, it is working:
var customCulture = new CultureInfo("en-US")
{
DateTimeFormat =
{
ShortDatePattern = "yyyy-MM-dd",
LongTimePattern = "HH:mm:ss.FFFFFFFK"
}
};
Console.WriteLine(DateTime.Now);
System.Threading.Thread.CurrentThread.CurrentCulture = customCulture;
System.Threading.Thread.CurrentThread.CurrentUICulture = customCulture;
Console.WriteLine(DateTime.Now);
Console.ReadLine();
However, Scott has titled his post Enabling Evil for reason. Think twice before doing that!
The T is not needed, but also can not be provided. If you still need it, you need to use Reflection, as Matt answered.

How To Get English Month Name From Hebrew Calendar In C#

I am trying to output a Hebrew calendar date in English with C#. The following outputs the date in Hebrew:
var ci = System.Globalization.CultureInfo.CreateSpecificCulture("he-IL");
ci.DateTimeFormat.Calendar = new System.Globalization.HebrewCalendar();
Response.Write(DateTime.Today.ToString("MMM d, yyyy", ci));
Response.Write(DateTime.Today.ToString("d-M-y", ci));
Gives
כסלו כ"ו, תשע"ה
כ"ו-ג'-תשע"ה
for December 18, 2014. Change the CultureInfo to "en-US" raises an "Not a valid calendar for the given culture." error. I am trying to get
26 Kislev 5775
and
26-09-5775

I could not figure out how to set the array of month names for leap years or the array of day numbers so that they are rendered as English numbers rather than hebrew letters. My solution was:
Globals.cs
public static string[] HebrewMonthNames =
{
"Tishrei",
"Cheshvan",
"Kislev",
"Tevet",
"Shevat",
"Adar",
"Nissan",
"Iyar",
"Sivan",
"Tamuz",
"Av",
"Elul"
};
public static string[] HebrewMonthNamesLeapYear =
{
"Tishrei",
"Cheshvan",
"Kislev",
"Tevet",
"Shevat",
"Adar I",
"Adar II",
"Nissan",
"Iyar",
"Sivan",
"Tamuz",
"Av",
"Elul"
};
Utils.cs
public string FormatHebrewDate(DateTime dtGregorian)
{
System.Globalization.HebrewCalendar hCal = new System.Globalization.HebrewCalendar();
string sDate = hCal.GetDayOfMonth(dtGregorian).ToString() + " ";
if (hCal.IsLeapYear(hCal.GetYear(dtGregorian)))
{
sDate += Globals.HebrewMonthNamesLeapYear[hCal.GetMonth(dtGregorian) - 1];
}
else
{
sDate += Globals.HebrewMonthNames[hCal.GetMonth(dtGregorian) - 1];
}
sDate += " " + hCal.GetYear(dtGregorian).ToString();
return sDate;
}

Option 1:
You can override the DateTimeFormatInfo.MonthNames and MonthGenitiveNames properties as well as their corresponding AbbreviatedMonthNames and AbbreviatedMonthGenitiveNames properties.
They are simple 1-dimensional string[] arrays and have a public setters, which allows you to add your custom translations to the CultureInfo:
When this property is set, the array must be one-dimensional and must
have exactly 13 elements. Calendar objects accommodate calendars with
13 months. The first element (the element at index zero) represents
the first month of the year defined by the Calendar property.
If you set the MonthNames property, you must also set the
MonthGenitiveNames property.
If the custom pattern includes the format pattern "MMMM",
DateTime.ToString displays the value of MonthNames in place of the
"MMMM" in the format pattern.
This property is affected if the value of the Calendar property
changes.
So you could modify your code example to this:
// I am just using German Number representations for the example.
// Use additional string Arrays to suit the abbrevated
// and the Genetive names.
// Replaye with whatever suits your needs.
string[] monthNames =
{
"Eins",
"Zwei",
"Drei",
"Vier",
"Fünf",
"Sechs",
"Sieben",
"Acht",
"Neun",
"Zehn",
"Elf",
"Zwölf",
string.Empty
};
// Assign each string Array to its corresponding property.
// I am using the same Array here just as an example for
// what is possible and because I am lazy... :-)
ci.DateTimeFormat.MonthNames = monthNames;
ci.DateTimeFormat.MonthGenitiveNames = monthNames;
ci.DateTimeFormat.AbbreviatedMonthNames = monthNames;
ci.DateTimeFormat.AbbreviatedMonthGenitiveNames = monthNames;
These names will then be used in with your format string in the output, just as you want it to have.
Each time you change the calendar, these overrides will be lost. So you need to make sure to re-assign the custom values if you need it.
[Update] Option 2:
A more persistent approach might be to use the CultureAndRegionInfoBuilder Class.
Defines a custom culture that is new or based on another culture and
country/region. The custom culture can be installed on a computer and
subsequently used by any application that is running on that computer.
You can either create a complete replacement version of the "he-IL" culture or create a variation with just your custom translations, or anything in between.
Using this approach you do not have to manually make sure that the translations are in place after each Culture-switch in the appliaction like in Option 1. Once the new Custom Culture is registered, you can use it like any other CultureInfo.
Please note that your application will need administrative priviledges to register a new Custom Culture.
The creation of a Custom Culture is not too complicated as the following code snippet shows.
Example from MSDN: CultureAndRegionInfoBuilder
The following example defines a custom ru-US culture that represents
the Russian language in the United States. The example defines the
custom culture by loading settings from the Russian (Russia)
CultureInfo object and the U.S. RegionInfo object, and then sets a
number of CultureAndRegionInfoBuilder properties. The example
registers the custom culture, and then instantiates it and makes it
the current thread culture.
using System;
using System.Globalization;
using System.Threading;
public class Example
{
public static void Main()
{
// Create a custom culture for ru-US.
CultureAndRegionInfoBuilder car1 = new CultureAndRegionInfoBuilder("ru-US",
CultureAndRegionModifiers.None);
car1.LoadDataFromCultureInfo(CultureInfo.CreateSpecificCulture("ru-RU"));
car1.LoadDataFromRegionInfo(new RegionInfo("en-US"));
car1.CultureEnglishName = "Russian (United States)";
car1.CultureNativeName = "русский (США)";
car1.CurrencyNativeName = "Доллар (США)";
car1.RegionNativeName = "США";
// Register the culture.
try {
car1.Register();
}
catch (InvalidOperationException) {
// Swallow the exception: the culture already is registered.
}
// Use the custom culture.
CultureInfo ci = CultureInfo.CreateSpecificCulture("ru-US");
Thread.CurrentThread.CurrentCulture = ci;
Console.WriteLine("Current Culture: {0}",
Thread.CurrentThread.CurrentCulture.Name);
Console.WriteLine("Writing System: {0}",
Thread.CurrentThread.CurrentCulture.TextInfo);
}
}
// The example displays the following output:
// Current Culture: ru-US
// Writing System: TextInfo - ru-US

I know this isn't an ideal answer, but you could manually input the list of Hebrew months, and use DateTime.Today.Month as an index into that list. Similarly, DateTime.Today.Day and .Year give integer output that you can use. Sorry, it seems a bit wrong to roll your own formatting, doesn't it?
You could still use string.format() to ensure it looks the way you want.

You can use this (I know it's not c#, but you should be able to get what I'm doing here):
Dim c As New CultureInfo("he-IL")
c.DateTimeFormat.Calendar.ToDateTime(Now.Year, Now.Month, Now.Day, Now.Hour, Now.Minute, Now.Second, Now.Millisecond).ToString("MMMM", New CultureInfo("en-GB"))
MessageBox.Show(c.DateTimeFormat.Calendar.ToDateTime(Now.Year, Now.Month, Now.Day, Now.Hour, Now.Minute, Now.Second, Now.Millisecond).ToString("MMMM", New CultureInfo("en-GB")))
But it will give you the Gregorian Calendar name (December)
piojo's suggestion to build up a dictionary object that contains the English version of the Hebrew name might work better

I do not believe that .NET has culture information that you want to use. However, you can create your own CultureInfo and modify the DateTimeFormat to suit your needs:
var cultureInfo = CultureInfo.CreateSpecificCulture("he-IL");
cultureInfo.DateTimeFormat.Calendar = new HebrewCalendar();
cultureInfo.DateTimeFormat.AbbreviatedMonthNames = new[] {
"Translation of תשרי",
"Translation of חשון",
// 11 more elements
};
cultureInfo.DateTimeFormat.AbbreviatedMonthGenitiveNames = new[] { ... };
cultureInfo.DateTimeFormat.MonthNames = new[] { ... };
cultureInfo.DateTimeFormat.MonthGenitiveNames = new[] { ... };
(Sorry for not providing the correct translations but I do not know Hebrew.)
You can then use this cultureInfo exactly as you do in your question.
If required you can also modify the day names in a similar fashion.
It is important that the calendar is set before modifying the various month and date name properties. The number of expected entries in the month name arrays changes as the calendar changes.

.NET - Canadian DateTime Format Bug

I currently have an application that needs to support multiple cultures. A date string is being passed in and is being parsed to a DateTime object. To allow for multiple cultures I am first setting the thread's culture and UICulture.
Here is an example of my code as it is:
First I set the culture for this thread. This is passed in on the URL (ex. en-us, en-ca, fr-ca):
CultureInfo ci = new CultureInfo(culture, false);
Thread.CurrentThread.CurrentUICulture = ci;
Thread.CurrentThread.CurrentCulture = ci;
I then take a date string that is also passed in on the URL and convert it to a DateTime. Depending on the culture the date will be passed in as mm/dd/yyyy or dd/mm/yyyy.
I parse the date strings with the following code:
DateTime DateTimeObject;
bool validDate = DateTime.TryParse(DateStringFromURL, Thread.CurrentThread.CurrentCulture, DateTimeStyles.None, out DateTimeObject);
The TryParse works for most cultures and out comes a valid datetime object. A problem arises with en-ca and fr-ca though. If the wrong format is passed in, the datestring does not parse correctly.
The following shows which format .NET seems to expect for each culture:
dd/MM/yyyy MM/dd/yyyy
EN-CA Valid Invalid
FR-CA Invalid Valid
EDIT:
To be more exact here are the examples causing me problems:
For EN-CA:
DateTime.Parse("26/08/2014") //VALID
DateTime.Parse("08/26/2014") //EXCEPTION THROWN
For FR-CA:
DateTime.Parse("26/08/2014") //EXCEPTION THROWN
DateTime.Parse("08/26/2014") //VALID
This is backwards from how other systems treat this culture's date formatting.
Why are the formats seemingly backwards?
Is this a bug with .NET 4.5?
Any and all help would be appreciated, thanks.
NOTE: .NET Version 4.5

You should probably look into Invariant culture. That is what you should use for your URL passing. You can use the local culture for display purposes on the client.
Typically, whenever you are storing data (for example, in a database or file ) it is best to use the Invariant culture. When displaying data you can use the local culture. When passing data around, you want to use Invariant culture.
Read more here.

I believe your assumptions are wrong. This console application:
static void Main(string[] args)
{
var enca = new CultureInfo("en-ca", false);
var frca = new CultureInfo("fr-ca", false);
Console.WriteLine("enca dd/MM/yyyy: " + ParseDate("26/08/2014", enca));
Console.WriteLine("enca MM/dd/yyyy: " + ParseDate("08/26/2014", enca));
Console.WriteLine("frca dd/MM/yyyy: " + ParseDate("26/08/2014", frca));
Console.WriteLine("frca MM/dd/yyyy: " + ParseDate("08/26/2014", frca));
Console.ReadKey();
}
static bool ParseDate(string date, CultureInfo culture)
{
try
{
DateTime.Parse(date, culture);
return true;
}
catch
{
return false;
}
}
Has output:
enca dd/MM/yyyy: False
enca MM/dd/yyyy: True
frca dd/MM/yyyy: False
frca MM/dd/yyyy: True

There is definitely a bug in data parsing for Canadian culture. If you try following having CurrentCulture = "en-CA":
DateTime.ParseExact("2014/09/20", "yyyy/MM/dd", Thread.CurrentThread.CurrentCulture)
you'll get following exception:
A first chance exception of type 'System.FormatException' occurred in mscorlib.dll
works fine if you replace / with something else, like - or with InvariantCulture.

Setting own culture or changing the current culture for datetime

I'm trying to set custom culture in my project. But I have some problem I've searched Google and found the following code. But I have some problems with it, please observe it in the comment.
using System;
using System.IO;
using System.Globalization;
public class Example
{
public static void Main()
{
// Persist the date and time data.
StreamWriter sw = new StreamWriter(#".\DateData.dat");
// Create a DateTime value.
DateTime dtIn = DateTime.Now;
// Retrieve a CultureInfo object.
CultureInfo invC = CultureInfo.InvariantCulture;
// Convert the date to a string and write it to a file.
sw.WriteLine(dtIn.ToString("r", invC));//what r mean?. if r is the custem culture variabel then how we determin it.
sw.Close();
// Restore the date and time data.
StreamReader sr = new StreamReader(#".\DateData.dat");
String input;
while ((input = sr.ReadLine()) != null)
{
Console.WriteLine("Stored data: {0}\n" , input);
// Parse the stored string.
DateTime dtOut = DateTime.Parse(input, invC, DateTimeStyles.RoundtripKind);
// Create a French (France) CultureInfo object.
CultureInfo frFr = new CultureInfo("fr-FR");
// Displays the date formatted for the "fr-FR" culture.
Console.WriteLine("Date formatted for the {0} culture: {1}" ,
frFr.Name, dtOut.ToString("f", frFr));// f?
// Creates a German (Germany) CultureInfo object.
CultureInfo deDe= new CultureInfo("de-De");
// Displays the date formatted for the "de-DE" culture.
Console.WriteLine("Date formatted for {0} culture: {1}" ,
deDe.Name, dtOut.ToString("f", deDe));
}
sr.Close();
}
}

Here's a link that shows many formatting values for the DateTime.ToString() method. I see no lower case "r" mentioned but the output of your code seems be the same with "R" or "r".
http://msdn.microsoft.com/en-us/library/zdtaw1bw.aspx
The DateTime value that you are writing to the file would be based on the invariant culture before any culture changes. You write it out and the you read it back in before getting some new culture information.
I had to guess at what you were asking because there is no question anywhere but in the code. Please provide more detail if I misunderstood what you are asking about.
Maybe if you were to show your output, it would help.
Ah, and here's a link that actually says that "r" is the same as "R". So now you have documentation for that part of your question:
http://msdn.microsoft.com/en-us/library/az4se3k1.aspx

Datetime value with different culture not formatting correctly

I'm having a slight issue with Thread culture and getting a date to display properly.
I am overloading the ToString() method of the DateTime class.
With culture "en-CA", my date is coming out in the right format "yyyy/MM/dd"
but with culture "fr-CA", my date is coming out "yyyy-MM-dd"
I've made some unit test to display the issue.
The english test works but the french always fails.
Even if I change the GetDateInStringMethod to do .ToShortDateString. I still get the same issue.
[Test()]
public void ValidInEnglish()
{
Thread.CurrentThread.CurrentCulture = new CultureInfo("en-CA");
Thread.CurrentThread.CurrentCulture.DateTimeFormat.ShortDatePattern = Utility.DatePattern;
DateTime? currentDate = new DateTime(2009,02,7);
string expected = "2009/02/07";
string actual = DateUtils.GetDateInString(currentDate);
//This works
Assert.AreEqual(expected, actual);
}
[Test()]
public void ValidInFrench()
{
Thread.CurrentThread.CurrentCulture = new CultureInfo("fr-CA");
Thread.CurrentThread.CurrentCulture.DateTimeFormat.ShortDatePattern = Utility.DatePattern;
DateTime? currentDate = new DateTime(2009, 02, 7);
string expected = "2009/02/07";
string actual = DateUtils.GetDateInString(currentDate);
// This doesn't work
Assert.AreEqual(expected, actual);
}
public static string GetDateInString(DateTime? obj)
{
if (obj == null || !obj.HasValue)
{
return string.Empty;
}
return obj.Value.ToString(Utility.DatePattern);
}
public const string DatePattern = "yyyy/MM/dd";

Change this line:
return obj.Value.ToString(Utility.DatePattern);
to this:
return obj.Value.ToString(Utility.DatePattern, CultureInfo.InvariantCulture);
Read about it here: System.Globalization.InvariantCulture

That doesn't work because using french culture defaults the datetime formatter to use - instead of / as a separator character. If you want to keep your date the same no matter the culture then use CultureInfo.InvariantCulture if you want to use the french formatting the change your expected test result to "2009-02-07". If you are looking for more info check this msdn link.
And if you want a personal recommendation for a lib to use for dealing with the awesomeness that is Globalization then I'd recommend Noda Time.