get startdate and enddate
DateTime StartingDate= DateTime.Now.AddDays(-30);
then get list of dates between these dates using below method
private List<datetime> GetDateRange(DateTime StartingDate, DateTime EndingDate)
{
if (StartingDate > EndingDate)
{
return null;
}
List<datetime> rv = new List<datetime>();
DateTime tmpDate = StartingDate;
do
{
rv.Add(tmpDate);
tmpDate = tmpDate.AddDays(1);
} while (tmpDate <= EndingDate);
return rv;
}