C#: Get sundays in month

using System.Globalization;

protected void PrintSundays(int year, int month, DayOfWeek dayName)
{
  CultureInfo ci = new CultureInfo("en-US");
  for (int i = 1 ; i <= ci.Calendar.GetDaysInMonth (year, month); i++)
  {
    if (new DateTime (year, month, i).DayOfWeek == dayName)
      Response.Write (i.ToString() + "
");
  }
}