Sub compter_uniques()
fin2 = Feuil13.Range("A65536").End(xlDown).Row ' taille du tableau recherche
Dim unique As Collection
Set unique = New Collection
On Error Resume Next
For C = 12 To 13
deb = Feuil8.Cells(1, C).Value
fin = DateSerial(Year(Feuil8.Cells(1, C).Value), Month(Feuil8.Cells(1, C).Value) + 1, 0)
For Each cel In Feuil3.Range("B2:B" & fin2)
If cel.Value >= deb And cel.Value <= fin Then unique.Add cel.Value, CStr(cel.Value)
Next cel
On Error GoTo 0
MsgBox "Eléments uniques : " & unique.Count
Next C
End Sub