c# - Bulkcopy with Date datatype -

i using bulkcopy transfer excel data sql 1 of field date format have return bellow code getting error while executing please me..

                sqlconnection myconnection;                  myconnection = new sqlconnection(connetionstring);                 myconnection.open();                  string reportfilenpath = system.appdomain.currentdomain.basedirectory + "inputfilefortool" + "\\outsourcemanualuploadfile.xlsx";                  // myconnection string excel workbook                 string excelconnectionstring = @"provider=microsoft.ace.oledb.12.0;data source=" + reportfilenpath + ";extended properties=excel 12.0;";                 nsheetname = cbosheetname.text;                 nsheetname = nsheetname.replace("$", "");                  // create myconnection excel workbook                 using (oledbconnection newconnection = new oledbconnection(excelconnectionstring))                 {                     oledbcommand command = new oledbcommand                              ("select * [" + nsheetname + "$]", newconnection);                     newconnection.open();                     oledbdatareader dr = command.executereader();                     // bulk copy sql server                     //sqlbulkcopy bulkcopy = new sqlbulkcopy(connetionstring,sqlbulkcopyoptions.keepidentity);                     using (sqlbulkcopy bc = new sqlbulkcopy(connetionstring, sqlbulkcopyoptions.keepidentity))                     //using (sqlbulkcopy bc = new sqlbulkcopy(connetionstring))                     {                         bc.columnmappings.clear();                         bc.destinationtablename = "outsourcemanualupload";                         bc.columnmappings.add("device", "device");                         bc.columnmappings.add("brand", "brand");                         bc.columnmappings.add("model", "model");                         bc.columnmappings.add("region", "region");                         bc.columnmappings.add("date", "date"));                         bc.columnmappings.add("resource", "resource");                         bc.writetoserver(dr);                     }                     newconnection.close();                 }                 myconnection.close();             }