Dim x As Range, y As Range, z As Range
Set x = Workbooks("classeur1.xls").Sheets("Feuil1").Range("A2")
With Workbooks("classeur2.xls").Sheets("Feuil1")
Set y = .Range("A1:A" & .Range("A65536").End(xlUp).Row)
End With
Set z = y.Find(x.Value, , xlValues, xlWhole, , , False)
If Not z Is Nothing Then MsgBox "la date est en " & z.Address