WORKDAYSMISC

Returns the serial number before or after a given number of days from a start date using a defined list of workdays.
For instructions on how to add a function to a workbook refer to the page under Inserting Functions

Option Base 1    

'lStartDate - The starting date.
'lDays - The number of valid days after the begin date that the event should take place.
'rgeHolidays - The dates to exclude from the working calendar, holidays and floating days.
'rgeWorkdays - The days of the week that you want to include.

Public Function WORKDAYSMISC(ByVal lStartDate As Long, _ 
                             ByVal lDays As Long, _ 
                             ByVal rgeHolidays As Range, _ 
                             ByVal rgeWorkDays As Range) As Long 
 
Dim iweekdaycount As Integer 
Dim bhasvalidworkday As Boolean 
Dim bisvalidworkday As Boolean 
Dim lnewdate As Long 
Dim idaycount As Integer 
Dim arholidays() As Long 
Dim iholidaycount As Integer 
Dim iarrayno As Integer 

   bhasvalidworkday = False 
   For iweekdaycount = 1 To 7 
      If rgeWorkDays.Item(iweekdaycount).Text <> "" Then bhasvalidworkday = True 
      If rgeWorkDays.Item(iweekdaycount).Text <> "" Then Exit For 
   Next iweekdaycount 
   
   If bhasvalidworkday = False Then Call MsgBox("The rgeWorkDays parameter is incorrect") 
   If bhasvalidworkday = False Then Exit Function 
   
   ReDim arholidays(rgeHolidays.Count) 
   For iholidaycount = 1 To rgeHolidays.Count 
      If rgeHolidays.Item(iholidaycount).Value <> "" Then 
         arholidays(iholidaycount) = rgeHolidays.Item(iholidaycount).Value 
      Else 
         Exit For 
      End If 
   Next iholidaycount 
   ReDim Preserve arholidays(iholidaycount - 1) 
   
   lnewdate = lStartDate 
   idaycount = lDays 
   
   Do Until idaycount = 0 
      bisvalidworkday = True 
   
      If lDays = 0 Then idaycount = 1 
      If lDays > 0 Then lnewdate = lnewdate + 1 
      If lDays < 0 Then lnewdate = lnewdate - 1 
   
      If rgeWorkDays.Item(VBA.Weekday(lnewdate)).Text <> "" Then 
         For iarrayno = 1 To UBound(arholidays) 
            If lnewdate = arholidays(iarrayno) Then 
               bisvalidworkday = False 
               Exit For 
            End If 
         Next iarrayno 
   
         If bisvalidworkday = True Then 
            If idaycount > 0 Then idaycount = idaycount - 1 
            If idaycount < 0 Then idaycount = idaycount + 1 
         End If 
      End If 
   Loop 
   WORKDAYSMISC = lnewdate 

End Function 

This user defined function is similar to the built-in WORKDAY function.