Convert.ToDateTime((Date.Text) to YYYY-MM-DD in VB code example
Example: vb string date to date format dd mm yyyy to yyyymmdd
//vb System.DateTime
DateTime date = DateTime.ParseExact(text, "dd/MM/yyyy",
CultureInfo.InvariantCulture);
string reformatted = date.ToString("yyyyMMdd", CultureInfo.InvariantCulture);