yyyy-MM-dd date format in Export to Excel
===

Is there any way for getting date alone from UniversalSortableDateTimePattern using this in Export to Excel function. The Excel doesn't accepts the date format..<br> I need to display as yyyy-MM-dd. 
Any suggestions ll be helpful ?
My code as

     dtASalesDrivers.Columns.Add(new System.Data.DataColumn("Start Date", typeof(String)));
    DateTime dt = Convert.ToDateTime(txtATrendStartDate.Text);
     drASalesDrivers[2] = string.Format("{0:yyyy-MM-dd}", dt);
    dtASalesDrivers.Rows.Add(drASalesDrivers);

Edit :


                DateTime dt = Convert.ToDateTime(txtATrendStartDate.Text);
                drASalesDrivers[2] = string.Format("{0:u}", dt);
This displays both date and time. Is there any way for displaying only date ???