String.FormatException with DateTime in non US Culture

8
votes

I am getting a String.FormatException trying to convert/parse a string when the culture is other than non-US. The odd thing is that the string was generated by applying the very same format and culture as those being used to parse it back into a string. In the code below, all of these versions will fail:

const string culture = "ja-JP";
const string format = "dd MMM yyyy"; //error in orignal post included {0:}
CultureInfo info = new CultureInfo(culture);
Thread.CurrentThread.CurrentCulture = info;
Thread.CurrentThread.CurrentUICulture = CultureInfo.CreateSpecificCulture(culture);

//string toParse = String.Format(info, format, DateTime.Now); //error in original post
string toParse = DateTime.Now.ToString(format);
System.Diagnostics.Debug.WriteLine(string.Format("Culture format = {0}, Date = {1}", culture, toParse));
try
{
    DateTime output = DateTime.ParseExact(toParse, format, CultureInfo.InvariantCulture);
    //DateTime output = DateTime.ParseExact(toParse, format, info);
    //DateTime output = DateTime.ParseExact(toParse, format, info, DateTimeStyles.None);
    //DateTime output = Convert.ToDateTime(toParse, info);
}
catch (Exception ex)
{
    System.Diagnostics.Debug.WriteLine(ex.Message);
}

Note that the string for en-US is "25 Feb 2010". The string for ja-JP is "25 2 2010".

Any idea how to get "25 2 2010" back into a date?

Thanks in advance.

Edit1: I should note that the Japanese culture is hard-coded here only as an example. I really need this to work with whatever culture is set by the user. What I need is a solution where the date time format works no matter what the user's culture. I think the single M does it.

Edit 2: M doesn't work for English. Anyone know a format string that works for all cultures?

4
c#datetimeculture

4 Answers

3
votes

If you change:

DateTime output = DateTime.ParseExact(
    toParse, format, CultureInfo.InvariantCulture);

to

DateTime output = DateTime.ParseExact(toParse, "dd MMM yyyy", info);

the date is correctly parsed.

Note that in your example you are using a culture (ja-JP) to convert to string but another culture to convert from string. Another problem is that String.Format accepts a composite format string ("My string to format - {0:dd MMM yyyy}"), but DateTime.ParseExact is expecting only the date time format.

0
votes

Try using a single M when parsing the date. That is what is used in the example for the MonthDayPattern for Japanese culture.

const string format = "{0:dd M yyyy}";
0
votes
string text = "25 2 2009";
DateTime date = DateTime.ParseExact(text, "d M yyyy", CultureInfo.InvariantCulture);
0
votes

The format pattern you pass to DateTime.ParseExact has to be just the date pattern, without the placeholder. And for JP culture, you need to use just one M since the dates are represented by numbers even when MMM is specified when converting to a string.

        const string culture = "ja-JP";
        const string FROM_STRING_FORMAT = "dd M yyyy";
        const string TO_STRING_FORMAT = "{0:" + FROM_STRING_FORMAT + "}";
        CultureInfo info = new CultureInfo(culture);
        Thread.CurrentThread.CurrentCulture = info;
        Thread.CurrentThread.CurrentUICulture = CultureInfo.CreateSpecificCulture(culture);

        string toParse = String.Format(info, TO_STRING_FORMAT, DateTime.Now);
        Console.WriteLine(string.Format("Culture format = {0}, Date = {1}", culture, toParse));
        try
        {
            DateTime output = DateTime.ParseExact(toParse, FROM_STRING_FORMAT, CultureInfo.InvariantCulture);
            Console.WriteLine(output);
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.Message);
        }