c# Date component bug or am i missing something?

Question

I have a huge problem with the following code:

DateTime date = DateTime.Now;
String yearmonthday = date.ToString("yyyy/MM/dd");
MessageBox.Show(yearmonthday);

the problem is, C# uses the system date separator instead of always using "/" as i specified. If I run that code, I get the following output:

2011/03/18

but if I go to "control panel" -> "regional and language options" and change the date separator to "-", I get

2011-03-18

Even if in the toString method I specified to use '/' . Am I missing something or this is a C# / .Net Framework bug?

Answer 1

Try like this:

String yearmonthday = date.ToString("yyyy/MM/dd", CultureInfo.InvariantCulture);

or escape the /

String yearmonthday = date.ToString(@"yyyy\/MM\/dd");

Answer 2

The / in your format string is a placeholder for the date separator -- the behaviour that you're seeing is by design and clearly documented.

If you need a literal / then you need to escape it in your format string, which should then look something like "yyyy\\/MM\\/dd" or "yyyy'/'MM'/'dd" .

Answer 3

The problem is that / is reserved for the date character - so this isn't a bug - it's a feature that this gets interpreted according to the locale.

Try escpaing the / character with:

var d = DateTime.Now;
d.ToString("yy\\/mm\\/dd").Dump();

Answer 4

InvariantCulture应该做到这一点

String yearmonthday = DateTime.Now.ToString("yyyy/MM/dd",CultureInfo.InvariantCulture); 

Answer 5

You can get '-' or ":" based on the formats that you supply . refer http://msdn.microsoft.com/en-us/library/zdtaw1bw.aspx

Answer 6

the / is a date separator:

http://msdn.microsoft.com/en-us/library/8kb3ddd4.aspx

if you need custom separator:

http://msdn.microsoft.com/en-us/library/8kb3ddd4.aspx#dateSeparator

so the behavior is correct

Answer 7

You can escape the / character, since it is the date separator, like this:

var d = DateTime.Now;
var s = d.ToString(@"yyyy\/MM\/dd");

Read all about it: http://msdn.microsoft.com/en-us/library/8kb3ddd4.aspx

Answer 8

This is apparently by design.

The work is implemented in an internal class called DateTimeFormat which you can see this snippet in FormatCustomized method:

 case '/':
        {
            outputBuffer.Append(dtfi.DateSeparator);
            num2 = 1;
            continue;
        }

So it replaces / with DateSeparator .