Posted by gabriel, Wed Aug 06 22:57:00 UTC 2008

Here’s a simple way of getting the number of business days between two dates using C#.

            DateTime dtBegin = new DateTime(2008, 8, 6);
            DateTime dtEnd = new DateTime(2008, 8, 13);

            int dayCount = 0;

            //while the End date is not reached
            while (dtEnd.CompareTo(dtBegin) > 0)
            {
                //check if the day is not a weekend day
                if ((dtBegin.DayOfWeek != DayOfWeek.Saturday) && (dtBegin.DayOfWeek != DayOfWeek.Sunday))
                {
                    dayCount++;
                }
                //go to next day
                dtBegin = dtBegin.AddDays(1);
            }

You can enhance this method consulting a list of holidays to check if the current date is indeed a business day. For this you have to have the list of holidays somewhere. In our example I’ll create a fake method that will provide the holidays list.

        public static void CalculateNumberOfWeekdays()
        {
            DateTime dtBegin = new DateTime(2008, 8, 6);
            DateTime dtEnd = new DateTime(2008, 8, 13);
            List<DateTime> holidays = GetHolidays();

            int dayCount = 0;

            //while the End date is not reached
            while (dtEnd.CompareTo(dtBegin) > 0)
            {
                //check if the day is not a weekend day
                if ((dtBegin.DayOfWeek != DayOfWeek.Saturday) 
                    && (dtBegin.DayOfWeek != DayOfWeek.Sunday)
                    && (!holidays.Contains(dtBegin)))
                {
                    dayCount++;
                }
                //go to next day
                dtBegin = dtBegin.AddDays(1);
            }
            Console.WriteLine(dayCount);
        }

        public static List<DateTime> GetHolidays()
        {
            List<DateTime> holidays = new List<DateTime>();
            holidays.Add(new DateTime(2008, 8, 7));
            return holidays;
        }            

See you next time.

Filed Under: Tips and Tutorials | Tags: .net C#