Calcule el número de días de la semana entre dos fechas en C#

Question

¿Cómo puedo obtener el número de días hábiles entre dos fechas determinadas sin tan solo recorrer las fechas entre y contando los días laborables?

Parece bastante sencillo, pero no puedo encontrar una respuesta correcta concluyente que cumpla con lo siguiente:

1. El total debe ser inclusivo, por lo que GetNumberOfWeekdays (new DateTime (2009,11,30), new DateTime (2009,12,4)) debe ser igual a 5, de lunes a viernes.
2. Debería permitirse para los días de salto
3. NO solo itera en todas las fechas intermedias mientras se cuentan los días de la semana.

He encontrado una pregunta similar con una answer que se acerca pero no es correcta

Answer 1

Aquí la función, que calcula la cuenta de DayOfWeek entre dos fechas. Sea cuidadoso, lo calcula de manera inclusiva (incluye el día de inicio y el día de finalización en el cálculo):

private int GetWeekdayCount(DayOfWeek dayOfWeek, DateTime begin, DateTime end)
    {
        if (begin < end)
        {
            var timeSpan = end.Subtract(begin);
            var fullDays = timeSpan.Days;
            var count = fullDays / 7; // количество дней равно как минимум количеству полных недель попавших в диапазон
            var remain = fullDays % 7; // остаток от деления

            // и вычислим попал ли еще один день в те куски недели, что остаются от полной
            if (remain > 0)
            {
                var dowBegin = (int)begin.DayOfWeek;
                var dowEnd = (int)end.DayOfWeek;
                var dowDay = (int)dayOfWeek;
                if (dowBegin < dowEnd)
                {
                    // когда день недели начала меньше дня недели конца, например:
                    //  начало       конец
                    //    //          //
                    //    -- -- -- -- --
                    // Вс Пн Вт Ср Чт Пт Сб
                    if (dowDay >= dowBegin && dowDay <= dowEnd)
                        count++;
                }
                else
                {
                    // когда день недели начала больше дня недели конца, например:
                    //   конец      начало
                    //    //          //
                    // -- --          -- --
                    // Вс Пн Вт Ср Чт Пт Сб
                    if (dowDay <= dowEnd || dowDay >= dowBegin)
                        count++;
                }
            }
            else if (begin.DayOfWeek == dayOfWeek)
                count++;

            return count;
        }
        return 0;
    }

Aquí hay otro análogo simple de la función anterior:

private int GetWeekdayCountStupid(DayOfWeek dayOfWeek, DateTime begin, DateTime end)
    {
        if (begin < end)
        {
            var count = 0;
            var day = begin;
            while (day <= end)
            {
                if (day.DayOfWeek == dayOfWeek)
                    count++;
                day = day.AddDays(1);
            }
            return count;
        }
        return 0;
    }

Y pruebas para ambas funciones:

    [TestMethod()]
    public void TestWeekdayCount()
    {
        var init = new DateTime(2000, 01, 01);
        for (int day = 0; day < 7; day++)
        {
            var dayOfWeek = (DayOfWeek)day;
            for (int shift = 0; shift < 8; shift++)
            {
                for (int i = 0; i < 365; i++)
                {
                    var begin = init.AddDays(shift);
                    var end = init.AddDays(shift + i);
                    var count1 = GetWeekdayCount(dayOfWeek, begin, end);
                    var count2 = GetWeekdayCountStupid(dayOfWeek, begin, end);
                    Assert.AreEqual(count1, count2);
                }
            }
        }
    }

Answer 2

Desde este link :

    public static int Weekdays(DateTime dtmStart, DateTime dtmEnd)
    {
        // This function includes the start and end date in the count if they fall on a weekday
        int dowStart = ((int)dtmStart.DayOfWeek == 0 ? 7 : (int)dtmStart.DayOfWeek);
        int dowEnd = ((int)dtmEnd.DayOfWeek == 0 ? 7 : (int)dtmEnd.DayOfWeek);
        TimeSpan tSpan = dtmEnd - dtmStart;
        if (dowStart <= dowEnd)
        {
            return (((tSpan.Days / 7) * 5) + Math.Max((Math.Min((dowEnd + 1), 6) - dowStart), 0));
        }
        return (((tSpan.Days / 7) * 5) + Math.Min((dowEnd + 6) - Math.Min(dowStart, 6), 5));
    }


  [1]: http://www.eggheadcafe.com/community/aspnet/2/44982/how-to-calculate-num-of-w.aspx

Pruebas (cada prueba devuelve 5):

    int ndays = Weekdays(new DateTime(2009, 11, 30), new DateTime(2009, 12, 4));
    System.Console.WriteLine(ndays);

    // leap year test
    ndays = Weekdays(new DateTime(2000, 2,27), new DateTime(2000, 3, 5));
    System.Console.WriteLine(ndays);

    // non leap year test
    ndays = Weekdays(new DateTime(2007, 2, 25), new DateTime(2007, 3, 4));
    System.Console.WriteLine(ndays);

Answer 3

Esto debería hacer mejor que la solución por dcp:

    /// <summary>
    /// Count Weekdays between two dates
    /// </summary>
    /// <param name="dtmStart">first date</param>
    /// <param name="dtmEnd">second date</param>
    /// <returns>weekdays between the two dates, including the start and end day</returns>
    internal static int getWeekdaysBetween(DateTime dtmStart, DateTime dtmEnd)
    {
        if (dtmStart > dtmEnd)
        {
            DateTime temp = dtmStart;
            dtmStart = dtmEnd;
            dtmEnd = temp;
        }

        /* Move border dates to the monday of the first full week and sunday of the last week */
        DateTime startMonday = dtmStart;
        int startDays = 1;
        while (startMonday.DayOfWeek != DayOfWeek.Monday)
        {
            if (startMonday.DayOfWeek != DayOfWeek.Saturday && startMonday.DayOfWeek != DayOfWeek.Sunday)
            {
                startDays++;
            }
            startMonday = startMonday.AddDays(1);
        }

        DateTime endSunday = dtmEnd;
        int endDays = 0;
        while (endSunday.DayOfWeek != DayOfWeek.Sunday)
        {
            if (endSunday.DayOfWeek != DayOfWeek.Saturday && endSunday.DayOfWeek != DayOfWeek.Sunday)
            {
                endDays++;
            }
            endSunday = endSunday.AddDays(1);
        }

        int weekDays;

        /* calculate weeks between full week border dates and fix the offset created by moving the border dates */
        weekDays = (Math.Max(0, (int)Math.Ceiling((endSunday - startMonday).TotalDays + 1)) / 7 * 5) + startDays - endDays;

        return weekDays;
    }

Answer 4

Funciones de utilidad para obtener un rango de fechas:

public IEnumerable<DateTime> GetDates(DateTime begin, int count)
{
    var first = new DateTime(begin.Year, begin.Month, begin.Day);
    var maxYield = Math.Abs(count);
    for (int i = 0; i < maxYield; i++)
    {
        if(count < 0)
            yield return first - TimeSpan.FromDays(i);
        else
            yield return first + TimeSpan.FromDays(i);      
    }
    yield break;
}

public IEnumerable<DateTime> GetDates(DateTime begin, DateTime end)
{
    var days = (int)Math.Ceiling((end - begin).TotalDays);
    return GetDates(begin, days);
}

Código de demostración LINQPad:

var begin = DateTime.Now;
var end = begin + TimeSpan.FromDays(14);

var dates = GetDates(begin, end);
var weekdays = dates.Count(x => x.DayOfWeek != DayOfWeek.Saturday && x.DayOfWeek != DayOfWeek.Sunday);
var mondays = dates.Count(x => x.DayOfWeek == DayOfWeek.Monday);
var firstThursday = dates
    .OrderBy(d => d)
    .FirstOrDefault(d => d.DayOfWeek == DayOfWeek.Thursday);

dates.Dump("Dates in Range");
weekdays.Dump("Count of Weekdays");
mondays.Dump("Count of Mondays");
firstThursday.Dump("First Thursday");

Answer 5

La respuesta de eFloh tenía un día adicional si el último día era sábado o domingo. Esto lo arreglaría.

     public static int Weekdays(DateTime dtmStart, DateTime dtmEnd)
    {
        if (dtmStart > dtmEnd)
        {
            DateTime temp = dtmStart;
            dtmStart = dtmEnd;
            dtmEnd = temp;
        }

        /* Move border dates to the monday of the first full week and sunday of the last week */
        DateTime startMonday = dtmStart;
        int startDays = 1;
        while (startMonday.DayOfWeek != DayOfWeek.Monday)
        {
            if (startMonday.DayOfWeek != DayOfWeek.Saturday && startMonday.DayOfWeek != DayOfWeek.Sunday)
            {
                startDays++;
            }
            startMonday = startMonday.AddDays(1);
        }

        DateTime endSunday = dtmEnd;
        int endDays = 0;
        while (endSunday.DayOfWeek != DayOfWeek.Sunday)
        {
            if (endSunday.DayOfWeek != DayOfWeek.Saturday && endSunday.DayOfWeek != DayOfWeek.Sunday)
            {
                endDays++;
            }
            endSunday = endSunday.AddDays(1);
        }

        int weekDays;

        /* calculate weeks between full week border dates and fix the offset created by moving the border dates */
        weekDays = (Math.Max(0, (int)Math.Ceiling((endSunday - startMonday).TotalDays + 1)) / 7 * 5) + startDays - endDays;

        if (dtmEnd.DayOfWeek == DayOfWeek.Saturday || dtmEnd.DayOfWeek == DayOfWeek.Sunday)
        {
            weekDays -= 1;
        }

        return weekDays; 

    }

Answer 6

Necesitaba positivos / negativos (no valores absolutos), así es como lo resolví:

    public static int WeekdayDifference(DateTime StartDate, DateTime EndDate)
    {
        DateTime thisDate = StartDate;
        int weekDays = 0;
        while (thisDate != EndDate)
        {
            if (thisDate.DayOfWeek != DayOfWeek.Saturday && thisDate.DayOfWeek != DayOfWeek.Sunday) { weekDays++; }
            if (EndDate > StartDate) { thisDate = thisDate.AddDays(1); } else { thisDate = thisDate.AddDays(-1); }
        }

        /* Determine if value is positive or negative */
        if (EndDate > StartDate) {
            return weekDays;
        }
        else
        {
            return weekDays * -1;
        }
    }

Answer 7

O (1) solución:

// Count days from d0 to d1 inclusive, excluding weekends
public static int countWeekDays(DateTime d0, DateTime d1)
{
    int ndays = 1 + Convert.ToInt32((d1 - d0).TotalDays);
    int nsaturdays = (ndays + Convert.ToInt32(d0.DayOfWeek)) / 7;
    return ndays - 2 * nsaturdays
           - (d0.DayOfWeek == DayOfWeek.Sunday ? 1 : 0)
           + (d1.DayOfWeek == DayOfWeek.Saturday ? 1 : 0);
}

Ejemplos para enero de 2014:

    January 2014
Su Mo Tu We Th Fr Sa
          1  2  3  4
 5  6  7  8  9 10 11
12 13 14 15 16 17 18
19 20 21 22 23 24 25
26 27 28 29 30 31

countWeekDays(new DateTime(2014, 1, 1), new DateTime(2014, 1, 1)); // 1
countWeekDays(new DateTime(2014, 1, 1), new DateTime(2014, 1, 2)); // 2
countWeekDays(new DateTime(2014, 1, 1), new DateTime(2014, 1, 3)); // 3
countWeekDays(new DateTime(2014, 1, 1), new DateTime(2014, 1, 4)); // 3
countWeekDays(new DateTime(2014, 1, 1), new DateTime(2014, 1, 5)); // 3
countWeekDays(new DateTime(2014, 1, 1), new DateTime(2014, 1, 6)); // 4

NB Las entradas de DateTime deben estar aproximadamente a la misma hora del día. Si está creando objetos DateTime basados ​​únicamente en el año, el mes y el día como en los ejemplos anteriores, entonces debería estar bien. Como ejemplo de contador, 12:01 a.m. del 1 de enero a las 11:59 p.m. El 2 de enero abarca solo 2 días, pero la función anterior contará 3 si usa esos tiempos.

Answer 8

  public static List<DateTime> Weekdays(DateTime startDate, DateTime endDate)
  {
      if (startDate > endDate)
      {
          Swap(ref startDate, ref endDate);
      }
      List<DateTime> days = new List<DateTime>();

      var ts = endDate - startDate;
      for (int i = 0; i < ts.TotalDays; i++)
      {
          var cur = startDate.AddDays(i);
          if (cur.DayOfWeek != DayOfWeek.Saturday && cur.DayOfWeek != DayOfWeek.Sunday)
              days.Add(cur);
          //if (startingDate.AddDays(i).DayOfWeek != DayOfWeek.Saturday || startingDate.AddDays(i).DayOfWeek != DayOfWeek.Sunday)
          //yield return startingDate.AddDays(i);
      }
      return days;
  }

E intercambiar fechas

  private static void Swap(ref DateTime startDate, ref DateTime endDate)
  {
      object a = startDate;
      startDate = endDate;
      endDate = (DateTime)a;
  }

Answer 9

var dates = new List<DateTime>();

        for (var dt = YourStartDate; dt <= YourEndDate; dt = dt.AddDays(1))
        {

            if (dt.DayOfWeek != DayOfWeek.Sunday && dt.DayOfWeek != DayOfWeek.Saturday)
            { dates.Add(dt); }

        }

en este código puede tener una lista de todos los días hábiles entre dos fechas.

Si desea el recuento de estas fechas, puede obtener fechas. dates.Count como un número entero. o si desea obtener cada día, puede unir la lista a una cadena.