Sub somme_du_mois()
selection_plage_date = Application.WorksheetFunction.Max(Range("B11", Range("b65536").End(xlUp)))
MsgBox Format(selection_plage_date, "mm/yyyy")
plage_mois_teste = Range("B11", Range("b65536").End(xlUp))
selection_plage_date1 = Application.WorksheetFunction.Max(plage_mois_teste)
MsgBox Format(selection_plage_date1, "mm/yyyy")
End Sub