Deadline = Registreringsdato + 4 hverdage

You could just add 4 days to the original and then keep looping until you get 4
http://support.microsoft.com/kb/210562

http://www.mssqlcity.com/Articles/UDF/DateTimeUDF.htm

that last link was more to SQL Server

I´m sorry, but I can´t see how this would work ... hint ?

The function http://support.microsoft.com/kb/210562
is called with two dates and it returns the number of working days between the two.

So if you call it with the registreringsdato and dateadd 4 days to that it will return 4 or less

If it returns less then you add another day and call it again until it returns 4.
So now you have the Registreringsdato + 4 hverdage, dont you?

but NOTE:
' Note that this function does not account for holidays

Yes, I can see that, but

  Work_Days(#21-02-2007#;#25-02-2007#)

returns 5 days, and not 3 as I have expected ( not counting sat and sun )

I had expected that this :

If Format(DateCnt, "ddd") <> "Sun" And _
        Format(DateCnt, "ddd") <> "Sat" Then
        EndDays = EndDays + 1
      End If

would have taken care of it, but it doesn´t seem to work

I'll have a play with it to see whats happening.

Work_Days(#21-02-2007#;#25-02-2007#)
returns 3 here

Try calling it with
Work_Days(#2007-02-21#,#2007-02-25#)

And youcan use this to add your days

Function Add4WorkingDays(inDate As Date) As Date
Dim outDate As Date
Dim i As Integer

    outDate = DateAdd("d", 4, inDate)
    i = Work_Days(inDate, outDate)
   
    Do Until i = 4
        outDate = DateAdd("d", 1, outDate)
        i = Work_Days(inDate, outDate)
   
    Loop
   
End Function

I´m sorry, I simply can´t make it work ... the last function you made, creates a Error 6 overflow.

There must be somethint wrong with my  installation

if you have danish regional settings then you will need to change , ; in functions.

This solved the problem ... my mistake

Format(DateCnt, "ddd") <> "sø" And _
Format(DateCnt, "ddd") <> "lø" Then

thanks, great to see it works, but it will very likley give problems if different regional settings are used. Maybe it can be modified to take the day number instead

You can always use the Weekday function instead - that's what I would do...