First of all, please read my comment.
Here is an example how to process with dates:
DateTime startdate = new DateTime(2013, 8, 1);
DateTime enddate = startdate.AddMonths(35);
DateTime currdate =startdate;
while (currdate <=enddate)
{
Console.WriteLine("MonthNo: {0}, MonthName: {1}, Year: {2}", currdate.Month.ToString(), currdate.ToString("MMMM"), currdate.Year.ToString());
currdate = currdate.AddMonths(1) ;
}
Console.ReadKey();