XL 2016 [RESOLU] DATEDIF() en semaine, faisable ?

Function DuréeEnClair(ByVal DuRest As Double) As String
Dim U As Long, DuUnit As Double, NbUnit As Long, K As Long, Trad As String
For U = 1 To 6
   DuUnit = Choose(U, 365.2425, 30.436875, 7, 1, 1 / 24, 1 / 1440)
   NbUnit = Int(DuRest / DuUnit)
   If NbUnit > 0 Or K > 0 Then K = K + 1: If K > 2 Then Exit Function
   If NbUnit > 0 Then
      Trad = NbUnit & " " & Choose(U, "an", "mois", "sem.", "jour", "heure", "min")
      If NbUnit * Choose(U, 1, 0, 0, 1, 1, 0) > 1 Then Trad = Trad & "s"
      If K = 2 Then DuréeEnClair = DuréeEnClair & " et "
      DuréeEnClair = DuréeEnClair & Trad: End If
   DuRest = DuRest - DuUnit * NbUnit: Next U
End Function

=DuréeEnClair(;[@DATE]-[@[DATE DE NAISSANCE]])

Function DuréeEnClair(ByVal DuRest As Double, Optional ByVal OPé As Long = -1) As String
Dim U As Long, DuUnit As Double, NbUnit As Long, Trad As String, Compter As Boolean, K As Long
For U = 1 To 6
   If DuRest = 0 Then Exit For
   If OPé > 0 And U > OPé Then Exit For
   DuUnit = Choose(U, 365.2425, 30.436875, 7, 1, 1 / 24, 1 / 1440)
   NbUnit = Int(DuRest / DuUnit)
   If NbUnit > 0 Then
      If OPé <= 0 Then Compter = True
      If Trad <> "" Then
         If DuréeEnClair <> "" Then
            DuréeEnClair = DuréeEnClair & ", " & Trad
         Else
            DuréeEnClair = Trad: End If
         End If
      Trad = NbUnit & " " & Choose(U, "an", "mois", "sem.", "jour", "heure", "min")
      If NbUnit * Choose(U, 1, 0, 0, 1, 1, 0) > 1 Then Trad = Trad & "s"
      DuRest = DuRest - DuUnit * NbUnit: End If
   If Compter Then K = K - 1: If K < OPé Then Exit For
   Next U
If Trad <> "" Then
   If DuréeEnClair <> "" Then
      DuréeEnClair = DuréeEnClair & " et " & Trad
   Else
      DuréeEnClair = Trad: End If
   End If
If OPé > 0 And DuréeEnClair = "" Then DuréeEnClair = "Moins d'1 " _
   & Choose(OPé, "an", "mois", "sem.", "jour", "heure", "min")
End Function