C# convert DateTime from one format to another

Question

I thought this would be a really simple, and i\'ve tried to google it and I keep getting the exception String was not recognized as a valid DateTime.

This i

Answer 1

You don't need the ParseExact method, the Parse method is sufficient because it allows your date representation. See DateTime - The string to parse for an overview of allowed input formats.

This means the following works:

string sample = "2013-10-21T14:10:49";
DateTime parsed = DateTime.Parse(sample);

Console.WriteLine(parsed.ToString("MM/dd/yyyy HH:mm:ss"));

And the result is:

10/21/2013 14:10:49

Answer 2

When you write DateTime.ParseExact(sample, "MM/dd/yyyy HH:mm", ...), you are saying that sample is in the format MM/dd/yyyy HH:mm. Since it is not, it throws an exception.

It's important to know that a DateTime does not have any format associated with it. It's only when you convert it to or from a string that format can come into play. You should probably use something like this:

string sample = "2013-10-21T14:10:49";
DateTime date31 = DateTime.Parse(sample, System.Globalization.CultureInfo.InvariantCulture);
string date31string = date31.ToString("MM/dd/yyyy HH:mm", System.Globalization.CultureInfo.InvariantCulture);
// date31string is "10/21/2013 14:10"

Instead of ParseExact, I used Parse, since the format is recognized by Parse, and I don't see much point in limiting what sort of formats it can accept to only that particular format.

Answer 3

Your string appears to be in format of "Xml-serialized". So it is the job of XmlConvert.

string sample = "2013-10-21T14:10:49";
string converted = XmlConvert.ToDateTime(sample, XmlDateTimeSerializationMode.Unspecified)
     .ToString("MM/dd/yyyy HH:mm", CultureInfo.InvariantCulture);