use the below program
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
namespace Date
{
class Program
{
static void Main(string[] args)
{
DataTable dt = new DataTable();
dt.Columns.Add(new DataColumn("PaymentDate", typeof(DateTime)));
dt.Columns.Add(new DataColumn("Payment", typeof(int)));
DataRow dr = dt.NewRow();
dr["PaymentDate"] = new DateTime(2012,10,12);
dr["Payment"] = 1200;
dt.Rows.Add(dr);
dr = dt.NewRow();
dr["PaymentDate"] = new DateTime(2013, 10, 24);
dr["Payment"] = 1200;
dt.Rows.Add(dr);
dr = dt.NewRow();
dr["PaymentDate"] = new DateTime(2013, 11, 23);
dr["Payment"] = 1200;
dt.Rows.Add(dr);
DataView dv = dt.DefaultView;
dv.RowFilter = "PaymentDate=Min(PaymentDate)";
Console.WriteLine(string.Format("The Payment is {0} on {1}", dv[0][1], dv[0][0]));
DateTime drLatesPayment = (DateTime)dt.Rows.OfType<datarow>().Min( r => r["PaymentDate"]);
Console.WriteLine(string.Format("The Payment is on {0}", drLatesPayment));
Console.Read();
}
}
}