Why does String.Format convert a forward slash into a minus sign?

Question

Why does String.Format("/") get converted to "-"?

Answer 1

I suspect that you are using the / symbol inside a {0} placeholder. It is a reserved symbol used as datetime separator in the given culture. You could escape it, like this:

string date = string.Format("{0:dd\\/MM\\/yyyy}", DateTime.Now);

Answer 2

As per Custom Date and Time Format Strings, / refers to the culture's date separator. So you need to escape it. You can either use a backslash as per Darin's answer, or you can quote it in single quotes. For example:

using System;
using System.Globalization;

class Test
{
    static void Main()
    {
        DateTime date = DateTime.Now;

        CultureInfo da = new CultureInfo("da");
        // Prints 09-08-2011
        Console.WriteLine(string.Format(da, "{0:dd/MM/yyyy}", date));
        // Prints 09/08/2011
        Console.WriteLine(string.Format(da, "{0:dd'/'MM'/'yyyy}", date));
        // Prints 09/08/2011
        Console.WriteLine(string.Format(da, "{0:dd\\/MM\\/yyyy}", date));
    }
}