Question

In DataTable i have this format mm/dd/yyyy hh:mm:ss AM
I want to change format to “dd.MM.yyyy”

 foreach (DataRow dr in dt.Rows)
      {
          dr["birth_day"]= String.Format("{0:dd.MM.yyyy}",dr["birth_day"]);
      }

It gave me this error:

String was not recognized as a valid DateTime.Couldn’t store <25.04.1988> in birth_day Column. Expected type is DateTime.

Answer 1

String format needs more than one argument, one for the string, and 1-n for each variable you have in the string.

e.g.

dr["birth_day"]= DateTime.Parse(String.Format("{0}:dd.MM.yyyy",dr["birth_day"]));

Though i am still not sure this would give what you want