Difference between two dates, ignoring weekend - working days only

Question

I was looking for something similar, but unfortunately I found nothing.

I found this solution that helped me a lot but is in Java. How to calculate the difference between two dates by ignoring weekends in Java without using a loop

I would like in C#.

How to return days between 2 dates ignoring weekends. Only weekdays?

Answer 1

I ended up making this code that works really well, I hope I can help other people.

   public static int GetDifDias(DateTime initialDate, DateTime finalDate)
        {
            var days = 0;
            var daysCount = 0;
            days = initialDate.Subtract(finalDate).Days;

            if (days < 0)
                days = days * -1;

            for (int i = 1; i <= days; i++)
            {
                initialDate = initialDate.AddDays(1);

                if (initialDate.DayOfWeek != DayOfWeek.Sunday &&
                    initialDate.DayOfWeek != DayOfWeek.Saturday)
                    daysCount++;
            }
            return daysCount;
        }

Answer 2

/// <summary>
/// Calculates number of business days, taking into account:
///  - weekends (Saturdays and Sundays)
///  - bank holidays in the middle of the week
/// </summary>
/// <param name="firstDay">First day in the time interval</param>
/// <param name="lastDay">Last day in the time interval</param>
/// <param name="bankHolidays">List of bank holidays excluding weekends</param>
/// <returns>Number of business days during the 'span'</returns>
public static int BusinessDaysUntil(this DateTime firstDay, DateTime lastDay, params DateTime[] bankHolidays)
{
    firstDay = firstDay.Date;
    lastDay = lastDay.Date;
    if (firstDay > lastDay)
        throw new ArgumentException("Incorrect last day " + lastDay);

    TimeSpan span = lastDay - firstDay;
    int businessDays = span.Days + 1;
    int fullWeekCount = businessDays / 7;
    // find out if there are weekends during the time exceedng the full weeks
    if (businessDays > fullWeekCount*7)
    {
        // we are here to find out if there is a 1-day or 2-days weekend
        // in the time interval remaining after subtracting the complete weeks
        int firstDayOfWeek = (int) firstDay.DayOfWeek;
        int lastDayOfWeek = (int) lastDay.DayOfWeek;
        if (lastDayOfWeek < firstDayOfWeek)
            lastDayOfWeek += 7;
        if (firstDayOfWeek <= 6)
        {
            if (lastDayOfWeek >= 7)// Both Saturday and Sunday are in the remaining time interval
                businessDays -= 2;
            else if (lastDayOfWeek >= 6)// Only Saturday is in the remaining time interval
                businessDays -= 1;
        }
        else if (firstDayOfWeek <= 7 && lastDayOfWeek >= 7)// Only Sunday is in the remaining time interval
            businessDays -= 1;
    }

    // subtract the weekends during the full weeks in the interval
    businessDays -= fullWeekCount + fullWeekCount;

    // subtract the number of bank holidays during the time interval
    foreach (DateTime bankHoliday in bankHolidays)
    {
        DateTime bh = bankHoliday.Date;
        if (firstDay <= bh && bh <= lastDay)
            --businessDays;
    }

    return businessDays;
}

I sucked that answer in the O.R.. She has the advantage that she can spend holidays. remembering that holiday is something that should be obtained from another source and may vary according to the municipality/state (not necessarily yours) and in which year is.

Behold working in the ideone. And in the .NET Fiddle. Also put on the Github for future reference.

Answer 3

One more way to join @Merson-js' lean solution with the @Maniero solution that includes holidays:

public static int CountDiasUteis(DateTime d1, DateTime d2, params DateTime[] bankHolidays)
{
    List<DateTime> datas = new List<DateTime>();

    for (DateTime i = d1.Date; i <= d2.Date; i = i.AddDays(1))
    {
        datas.Add(i);
    }

    return datas.Count(d => d.DayOfWeek != DayOfWeek.Saturday &&
                            d.DayOfWeek != DayOfWeek.Sunday &&
                            !bankHolidays.Contains(d));
}

Answer 4

Friends, just one more way to go:

public static int CountDiasUteis(DateTime d1, DateTime d2) {

   int fator = (d1 > d2 ? -1: 1);

   List<DateTime> datas = new List<DateTime>();

   for (DateTime i = d1.Date; (fator==-1 ? i >= d2.Date : i <= d2.Date); i = i.AddDays(fator)) {
      datas.Add(i);
   }

   return datas.Count(d => d.DayOfWeek != DayOfWeek.Saturday && 
                           d.DayOfWeek != DayOfWeek.Sunday) * fator;            

}