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

Replace algorithm in Informix 4GL so I can find it later.

DEFINE
   str_hitext           CHAR(130),
   str_text             CHAR(130),
   str_escape           CHAR(1)

   LET str_escape = ASCII 27

FUNCTION replace_algorithm()

DEFINE
   int_temp2            INTEGER,
   int_hipos            INTEGER,
   int_hipos_old        INTEGER,
   int_pos              INTEGER

   # remove highlight characters from text
   LET int_temp2 = LENGTH(str_hitext)
   LET int_pos = 1
   LET str_text = " "
  
   # cycle through highlight string looking for highlight strings
   LET int_hipos = 1
   LET int_hipos_old = 1
   WHILE int_hipos <= int_temp2 - 7

      # if we found an escape character (start of highlight sequence)
      IF str_hitext[int_hipos, int_hipos] = str_escape THEN

         # if a highlight sequence
         IF str_hitext[int_hipos + 1, int_hipos + 7] = "[32703m" OR str_hitext[int_hipos + 1, int_hipos + 7] = "[32723m" THEN
 
            # if there is previous data to copy over
            IF int_hipos - 1 >= int_hipos_old THEN

               # copy data over
               LET str_text[int_pos, int_pos + int_hipos - 1 - int_hipos_old] = str_hitext[int_hipos_old, int_hipos - 1]
               LET int_pos = int_pos + int_hipos - int_hipos_old

            END IF

            # move source positions - don't copy this over
            LET int_hipos = int_hipos + 8
            LET int_hipos_old = int_hipos

         # if not a highlight sequence
         ELSE

            # move source position
            LET int_hipos = int_hipos + 1

         END IF

      # if we didn't find an escape character
      ELSE

         # move source position
         LET int_hipos = int_hipos + 1

      END IF

   END WHILE

   # if there is previous data to copy over
   IF int_temp2 >= int_hipos_old THEN

      # copy data over
      LET str_text[int_pos, int_pos + int_temp2 - int_hipos_old] = str_hitext[int_hipos_old, int_temp2]

   END IF 

END FUNCTION