public static string toXsdDate(DateTime dateTime)
{
string year = dateTime.Year.ToString();
string month = dateTime.Month.ToString();
if (dateTime.Month < 10)
{
month = "0" + month;
}
string day = dateTime.Day.ToString();
if (dateTime.Day < 10)
{
day = "0" + day;
}
return year + "-" + month + "-" + day;
}