Set Default DateTime Format c#

Question

Is there a way of setting or overriding the default DateTime format for an entire application. I am writing an app in C# .Net MVC 1.0 and use alot of generics and reflection. Would be much simpler if I could override the default DateTime.ToString() format to be "dd-MMM-yyyy". I do not want this format to change when the site is run on a different machine.

Edit - Just to clarify I mean specifically calling the ToString, not some other extension function, this is because of the reflection / generated code. Would be easier to just change the ToString output.

Stair

Answer 1

The "default format" of a datetime is:

ShortDatePattern + ' ' + LongTimePattern

at least in the current mono implementation. This is particularly painful in case you want to display something like 2001-02-03T04:05:06Z i.e. the date and time combined as specified in ISO 8606, but not a big problem in your case:

using System;
using System.Globalization;
using System.Threading;

namespace test {
    public static class Program {
        public static void Main() {
            CultureInfo culture = (CultureInfo)CultureInfo.CurrentCulture.Clone();
            culture.DateTimeFormat.ShortDatePattern = "dd-MMM-yyyy";
            culture.DateTimeFormat.LongTimePattern = "";
            Thread.CurrentThread.CurrentCulture = culture;
            Console.WriteLine(DateTime.Now);
        }
    }
}

This will set the default behavior of ToString on datetimes to return the format you expect.

Beasley

Thanks for the reply, where should this code be put in a .Net MVC 1.0 project, I have tried in the view and it works, but not in the global.asax – Stair

What do you mean by "in the view"? And what did you do in the global.asax exactly? – Beasley

If I put <% CultureInfo culture = (CultureInfo)CultureInfo.CurrentCulture.Clone(); culture.DateTimeFormat.ShortDatePattern = "dd-MMM-yyyy"; culture.DateTimeFormat.LongTimePattern = ""; Thread.CurrentThread.CurrentCulture = culture; %> at the top of the View it formats all the DateTimes on the page correctly. However when I put that code in the Application_Start of the global.asax it does not work. I presume this has got to do with the multiple threading of the requests in IIS. Where is the best place to put this code to affect my whole site. – Stair

I would try Application_BeginRequest, but I think you'd better ask a new question... – Beasley

This is a good answer. The only problem is that a space is appended at the end. Is there any way how to remove that space? ShortDatePattern + ' ' + LongTimePattern – Areopagus

Answer 2

It is dependent on your application's localization-settings. Change that accordingly to get correct format.

Otherwise have a helper-class or an extension-method which always handles your DateTime.

public static string ToMyDateTime(this DateTime dateTime) {
    return dateTime.ToString("dd-MMMM-yy");
}

Electioneer

Answer 3

Using .Net 6 put something like this in your program.cs after app.UseAuthentication()/app.UseAuthorization() and before app.MapControllerRoute(...):

var ci = new CultureInfo("en-US");
ci.DateTimeFormat.ShortDatePattern = "MM/dd/yyyy";
app.UseRequestLocalization(new RequestLocalizationOptions
{
    DefaultRequestCulture = new Microsoft.AspNetCore.Localization.RequestCulture(ci),
    SupportedCultures = new List<CultureInfo> { ci },
    SupportedUICultures = new List<CultureInfo> { ci }
});

Here I'm changing the short date format, but you can also change currency symbol, decimal separator, etc.

Erdei

Answer 4

DateTime.ToString() combines the custom format strings returned by the ShortDatePattern and LongTimePattern properties of the DateTimeFormatInfo. You can specify these patterns in DateTimeFormatInfo.CurrentInfo.

I've never tried this my self.

Tepper

Answer 5

If you want to be sure that your culture stays the same, just set it yourself to avoid troubles.

System.Globalization.CultureInfo ci = new System.Globalization.CultureInfo("nl-BE");
System.Threading.Thread.CurrentThread.CurrentCulture = ci;
System.Threading.Thread.CurrentThread.CurrentUICulture = ci;

The above example sets the culture of the thread to Belgian-Dutch.

CurrentCulture does all the date and time handling and CurrentUICulture handles UI localization like resources.

Totalitarianism

Answer 6

I'm not sure if this would work for a web app, but you could try to set the DateTimeFormat property for the current culture.

Check this and specially this.

Abhorrent

Answer 7

You can write an ExtensionMethod like this:

public static string ToMyString(this DateTime dateTime)
{
  return dateTime.ToString("needed format");
}

Malvinamalvino