work days between two dates without cycling through dates

Will_Rickards (Will Rickards) — Thu, 13 Oct 2005 23:24:13 GMT

I was thinking about how to optimize figuring out the work days between two dates and came up with this function. It doesn't take into account holidays. You would have to take out the workdays for holidays from the number if you want to take into account holidays, but that should be easy enough.

4GL Version

 

# workdays

# returns the number of working days between two dates

FUNCTION workdays( dt_begin, dt_end )



DEFINE

   dt_begin             DATE,

   dt_end               DATE,

   dt_first_sunday      DATE,

   dt_last_saturday     DATE,

   int_workdays         INTEGER



   # get first sunday

   LET dt_first_sunday = dt_begin + ((7 - WEEKDAY(dt_begin)) MOD 7)



   # get last saturday

   LET dt_last_saturday = dt_end + ((-1 * (WEEKDAY(dt_end) + 1)) MOD 7)



   # get work weeks between first sunday and last saturday

   LET int_workdays = (((dt_last_saturday - dt_first_sunday) + 1) / 7) * 5

   

   # if first sunday is not begin date

   IF dt_first_sunday <> dt_begin THEN



      # assume first sunday is after begin date

      # add workdays from begin date to first sunday

      LET int_workdays = int_workdays + (6 - WEEKDAY(dt_begin))



   END IF



   # if last saturday is not end date

   IF dt_last_saturday <> dt_end THEN



      # assume last saturday is before end date

      # add workdays from last saturday to end date

      LET int_workdays = int_workdays + WEEKDAY(dt_end)  

  

   END IF



   # return working days

   RETURN int_workdays



END FUNCTION

VBA Version



' WorkDays

' returns the number of working days between two dates

Public Function WorkDays(ByVal dtBegin As Date, ByVal dtEnd As Date) As Long



   Dim dtFirstSunday As Date

   Dim dtLastSaturday As Date

   Dim lngWorkDays As Long



   ' get first sunday in range

   dtFirstSunday = dtBegin + ((8 - Weekday(dtBegin)) Mod 7)



   ' get last saturday in range

   dtLastSaturday = dtEnd - (Weekday(dtEnd) Mod 7)



   ' get work days between first sunday and last saturday

   lngWorkDays = (((dtLastSaturday - dtFirstSunday) + 1) / 7) * 5



   ' if first sunday is not begin date

   If dtFirstSunday <> dtBegin Then



      ' assume first sunday is after begin date

      ' add workdays from begin date to first sunday

      lngWorkDays = lngWorkDays + (7 - Weekday(dtBegin))



   End If



   ' if last saturday is not end date

   If dtLastSaturday <> dtEnd Then



      ' assume last saturday is before end date

      ' add workdays from last saturday to end date

      lngWorkDays = lngWorkDays + (Weekday(dtEnd) - 1)



   End If



   ' return working days

   WorkDays = lngWorkDays



End Function

DZone Snippets: informix code

work days between two dates without cycling through dates