Public Function IsWorkDay(Target As Excel.Range) As String
    Dim n As Byte
 
    If Target Is Nothing Then Exit Function
    If Not IsDate(Target.Value) Then 
          IsWorkDay = "#WERT!"
          Exit Function
    End If
    n = WeekDay(Target.Value)
    If n = 1 Or n = 7 Then
       IsWorkDay = "NEIN"
    Else
       IsWorkDay = "Ja"
    End If
 
End Function
 
Public Function GetDayName(Target As Excel.Range) As String
 
    If Target Is Nothing Then Exit Function
    If Not IsDate(Target.Value) Then 
           GetDayName = "#WERT!"
           Exit Function
    End If
    GetDayName = Choose(WeekDay(Target.Value), "Sonntag", "Montag", "Dienstag", _
                        "Mittwoch", "Donnerstag", "Freitag", _
                        "Samstag")
End Function