Hi Friend I have solved this using that code
string date = "";
DateTime newdate,d1;
if (e.Row.RowType == DataControlRowType.DataRow)
{
for (int i = 1; i < e.Row.Cells.Count; i++)
{
date = e.Row.Cells[i].Text.ToString();
if(date.Length>7)
{
if (DateTime.TryParse(date, out newdate))
{
d1 = newdate.Date;
e.Row.Cells[i].Text = d1.Date.ToString("MM/dd/yyyy");
}
}
}
}