Adding Business days to a date

Hi Prasanna,

This is the most straightforward way of adding any number of business days to a given date (it can also cope with subtraction by adding a negative number of days). It's not very efficient when adding a large number of days (I could supply a more efficient method if you need it) but, for most practical purposes, it will still be quick enough:

using System;

class Program
{
    static void Main()
    {
       string startDate1 = "09/24/2007 10:00:00";
       int increment1 = 5;
       string endDate1  = AddBusinessDays(startDate1, increment1);
       Console.WriteLine("{0} plus {1} business days is {2}", startDate1, increment1, endDate1);        
       string startDate2 = "09/28/2007 10:00:00";
       int increment2 = 4;
       string endDate2  = AddBusinessDays(startDate2, increment2);
       Console.WriteLine("{0} plus {1} business days is {2}", startDate2, increment2, endDate2);        
       Console.ReadKey();
    }

    public static string AddBusinessDays(string startDate, int numDays)
    {
       string format = "MM/dd/yyyy HH:mm:ss";
       DateTime dt = DateTime.ParseExact(startDate, format, null);
       if (numDays == 0) return startDate;
       if (numDays > 0)
       {
          for (int count = 1; count <= numDays; count++)
          {
             dt = dt.AddDays(1);
             if (dt.DayOfWeek == DayOfWeek.Saturday)
                dt = dt.AddDays(2);
             else if (dt.DayOfWeek == DayOfWeek.Sunday)
                dt = dt.AddDays(1);
          }
       }
       else
       {

          for (int count = 1; count <= -numDays; count++)
          {
             dt = dt.AddDays(-1);
             if (dt.DayOfWeek == DayOfWeek.Saturday)
                dt = dt.AddDays(-1);
             else if (dt.DayOfWeek == DayOfWeek.Sunday)
                dt = dt.AddDays(-2);
          }
       }
       return dt.ToString(format);      
    }
}