///<summary>Calculates the due date by adding the number of business days listed. Adds an additional day for each office holiday.</summary> public static DateTime ComputeDueDate(DateTime startDate, int days) { DateTime date = startDate; int counter = 0; while (counter < days) { date = date.AddDays(1); if (date.DayOfWeek == DayOfWeek.Saturday || date.DayOfWeek == DayOfWeek.Sunday) { continue; } if (Schedules.DateIsHoliday(date)) { continue; } counter++; } return(date + TimeSpan.FromHours(17)); //always due at 5pm on day specified. }