string “3/21/2013” is not recognized as valid datetime

[Arapahoe]

I am trying to convert a string to a datetime format in C#. \[code\]DateTime SnapDate = Convert.ToDateTime(valid(odr, 4)).Date;protected string valid(OleDbDataReader myreader, int stval)//if any columns are found null then they are replaced by zero{ object val = myreader[stval]; if (val != DBNull.Value) return val.ToString(); else return Convert.ToString("");}\[/code\]And it gives me the following error: "The string was not recognized as a valid DateTime. There is a unknown word starting at index 0."I tried several things like: \[code\]parse\[/code\] and \[code\]parseExact\[/code\] but still didn't get it.I am reading this data from an excel sheet.