ansaurus

Question

Calculating a date around working days/hours?

Answer 1

+1 A:

There's a recursive solution that could work, try thinking along these lines:

public DateTime getDeadline(SubmitTime, ProjectTimeAllowed)
{
   if (SubmitTime+ProjectTimeAllowed >= DayEndTime)
           return getDeadline(NextDayStart, ProjectTimeAllowed-DayEndTime-SubmitTime)
   else
           return SubmitTime + ProjectTimeAllowed
}

Obviously this is quite rough pseudocode. Hopefully it just gives you another way to think about the problem.

Ian Jacobs 2008-10-10 17:17:58

Answer 2

+1 A:

Here's how I would do it. The algorithm is to see whether the issue can be closed today and if not, use all of today's time to reduce the issue's remaining time and go to tomorrow.

Find the time you have to close the issue as a TimeSpan (I'm calling this the issue's remaining time)
For each working day, create a DateTime that has only the time of the start and end.
Set the start time to now.
Loop:
1. Find today's remaining time by subtracting today's end time minus the start time (the result should be a TimeSpan)
2. If today's remaining time is greater than the issue's remaining time, take today's date and today's starttime + issue remaining time
3. If the issue's remaining time is greater, set the issue's remaining time to be the issue's remaining time minus today's remaining time, move to tomorrow, and go to the top of the loop.

Dan Goldstein 2008-10-10 19:35:09

Answer 3

+1 A:

Using Stu's answer as a starting point, modify the IsInBusinessHours function to look up you business hours for the date parameter. A procedure like the following could be used:

CREATE PROCEDURE [dbo].[IsInBusinessHours]
    @MyDate DateTime 
AS
BEGIN
    SELECT     CASE Count(*) WHEN 0 THEN 0 ELSE 1 END AS IsBusinessHour
FROM         WorkHours
WHERE     (DATEPART(hour, StartHours) <= DATEPART(hour, @MyDate)) AND (DATEPART(hour, EndHours) > DATEPART(hour, @MyDate)) AND (Day = DATEPART(WEEKDAY, 
                      @MyDate))
END

Loscas 2008-10-10 19:43:07

Answer 4

+1 A:

Here's some C# code which might help, it could be much cleaner, but it's a quick first draft.

    class Program
    {
     static void Main(string[] args)
     {
      // Test
      DateTime deadline = DeadlineManager.CalculateDeadline(DateTime.Now, new TimeSpan(4, 0, 0));
      Console.WriteLine(deadline);
      Console.ReadLine();
     }
    }

    static class DeadlineManager
    {
     public static DateTime CalculateDeadline(DateTime start, TimeSpan workhours)
     {
      DateTime current = new DateTime(start.Year, start.Month, start.Day, start.Hour, start.Minute, 0);
      while(workhours.TotalMinutes > 0)
      {
       DayOfWeek dayOfWeek = current.DayOfWeek;
       Workday workday = Workday.GetWorkday(dayOfWeek);
       if(workday == null)
       {
        DayOfWeek original = dayOfWeek;
        while (workday == null)
        {
         current = current.AddDays(1);
         dayOfWeek = current.DayOfWeek;
         workday = Workday.GetWorkday(dayOfWeek);
         if (dayOfWeek == original)
         {
          throw new InvalidOperationException("no work days");
         }
        }
        current = current.AddHours(workday.startTime.Hour - current.Hour);
        current = current.AddMinutes(workday.startTime.Minute - current.Minute);
       }

       TimeSpan worked = Workday.WorkHours(workday, current);
       if (workhours > worked)
       {
        workhours = workhours - worked;
        // Add one day and reset hour/minutes
        current = current.Add(new TimeSpan(1, current.Hour * -1, current.Minute * -1, 0));
       }
       else
       {
        current.Add(workhours);
        return current;
       }
      }
      return DateTime.MinValue;
     }
    }

    class Workday
    {
     private static readonly Dictionary<DayOfWeek, Workday> Workdays = new Dictionary<DayOfWeek, Workday>(7);
     static Workday()
     {
      Workdays.Add(DayOfWeek.Monday, new Workday(DayOfWeek.Monday, new DateTime(1, 1, 1, 10, 0, 0), new DateTime(1, 1, 1, 16, 0, 0)));
      Workdays.Add(DayOfWeek.Tuesday, new Workday(DayOfWeek.Tuesday, new DateTime(1, 1, 1, 10, 0, 0), new DateTime(1, 1, 1, 16, 0, 0)));
      Workdays.Add(DayOfWeek.Wednesday, new Workday(DayOfWeek.Wednesday, new DateTime(1, 1, 1, 10, 0, 0), new DateTime(1, 1, 1, 16, 0, 0)));
      Workdays.Add(DayOfWeek.Thursday, new Workday(DayOfWeek.Thursday, new DateTime(1, 1, 1, 10, 0, 0), new DateTime(1, 1, 1, 16, 0, 0)));
      Workdays.Add(DayOfWeek.Friday, new Workday(DayOfWeek.Friday, new DateTime(1, 1, 1, 10, 0, 0), new DateTime(1, 1, 1, 14, 0, 0)));
     }

     public static Workday GetWorkday(DayOfWeek dayofWeek)
     {
      if (Workdays.ContainsKey(dayofWeek))
      {
       return Workdays[dayofWeek];
      }
      else return null;
     }

     public static TimeSpan WorkHours(Workday workday, DateTime time)
     {
      DateTime sTime = new DateTime(time.Year, time.Month, time.Day,
       workday.startTime.Hour, workday.startTime.Millisecond, workday.startTime.Second);
      DateTime eTime = new DateTime(time.Year, time.Month, time.Day,
       workday.endTime.Hour, workday.endTime.Millisecond, workday.endTime.Second);
      if (sTime < time)
      {
       sTime = time;
      }
      TimeSpan span = eTime - sTime;
      return span;
     }

     public static DayOfWeek GetNextWeekday(DayOfWeek dayOfWeek)
     {
      int i = (dayOfWeek == DayOfWeek.Saturday) ? 0 : ((int)dayOfWeek) + 1;
      return (DayOfWeek)i;
     }


     private Workday(DayOfWeek dayOfWeek, DateTime start, DateTime end)
     {
      this.dayOfWeek = dayOfWeek;
      this.startTime = start;
      this.endTime = end;
     }

     public DayOfWeek dayOfWeek;
     public DateTime startTime;
     public DateTime endTime;
    }

Esteban Brenes 2008-10-10 19:46:14

ansaurus

tags:

views:

answers:

Calculating a date around working days/hours?

related questions