String was not recognized as a valid DateTime for format yyMMdd

Question

I have a string like below :

"9/30/2017 12:00:00 AM"

Would love to convert it to format yyMMdd

 var evan = dataRow["ValueDate"].ToString(); //Output is "9/30/2017 12:00:00 AM"  
 DateTime dt = DateTime.ParseExact(evan,"yyMMdd",CultureInfo.InvariantCulture);

Than to diplay :

dt.ToString("yyMMdd");

Error Message : String was not recognized as a valid DateTime for format yyMMdd

What is my mistake?

Thank you

Answer 1

ParseExact is for parsing a string that's being input in a specific format. To display the string, you pass the format string to the ToString method:

var evan = dataRow["ValueDate"].ToString("yyMMdd");

Answer 2

DateTime.ParseExact is expecting the data you give it to be in the EXACT format you specify. Your string 9/30/2017 12:00:00 AM does not match your format yyMMdd . So either try using just DateTime.Parse , or make your format match the data. Something like

DateTime dt = DateTime.ParseExact(evan,"M/dd/yyyy HH:mm:ss tt",CultureInfo.InvariantCulture);`

Then you should be able to do dt.ToString("yyMMdd");

Answer 3

After gathering intel from posters I succed in understanding and solving my mistake :

After carefully consulting MSDN this is the solution I was looking for :

Input :

dataRow["ValueDate"].ToString() //  "9/30/2017 12:00:00 AM"

Code :

 DateTime convertedDate;
 convertedDate=Convert.ToDateTime(dataRow["ValueDate"].ToString());
 var evan = convertedDate.ToString("yyMMdd");  

Output :

"170930" //just like I need

Like Michael sharp explained earlier :

DateTime.ParseExact is expecting the data you give it to be in the EXACT format you specify. My string 9/30/2017 12:00:00 AM did not match my format yyMMdd