Sub ChangeDate()
Range("D4").NumberFormat = "m/d/yyyy"
End Sub
Sub Convertir()
Dim a, tablo, i&, x$, j%
a = Array("lundi", "mardi", "mercredi", "jeudi", "vendredi", "samedi", "dimanche")
With [A1].CurrentRegion.Columns(1) 'plage à adapter
tablo = .Value2
For i = 1 To UBound(tablo)
x = LCase(tablo(i, 1))
For j = 0 To 6
x = Replace(x, a(j), "")
Next j
x = Format(x, "dd/mm/yyyy")
If IsDate(x) Then tablo(i, 1) = CDate(x)
Next i
.NumberFormat = "dd/mm/yyyy"
.Value = tablo 'restitution
End With
End Sub