Splits a date range of 1 year on a monthly basis.

MonthlySplit.cs

public static class Program
{
	public static void Main(string[] arga)
	{
		const int TOTAL_MONTHS = 12;

		var fromDate = new DateTime(2013, 08, 15);
		var toDate = new DateTime(2014, 08, 14);

		var totalDays = 0;

		var monthlyEndDate = toDate;

		for (var monthCount = 1; monthCount <= TOTAL_MONTHS; monthCount++)
		{
			var monthlyStartDate = fromDate.AddMonths(TOTAL_MONTHS - monthCount);

			var dayCount = (monthlyEndDate.Subtract(monthlyStartDate).Days + 1);
			Console.WriteLine
				(
					monthCount.ToString("00") + ") " +
					"From: " + monthlyStartDate.ToString("dd-MMM-yyyy") + " to " + monthlyEndDate.ToString("dd-MMM-yyyy") +
					" => " + dayCount + " days."
				);

			totalDays += dayCount;

			monthlyEndDate = monthlyStartDate.AddDays(-1);
		}

		Console.WriteLine();
		Console.WriteLine("Total days: " + totalDays);

		Console.Read();
	}