Sub test_2()
Dim i&, j&, T As Variant, Plg As Range
With Sheets("Feuil1")
Set Plg = .Range(.Cells(2, 2), .Cells(.Rows.Count, 1).End(3)(1, 3))
End With
T = Plg
For i = LBound(T, 1) To UBound(T, 1)
For j = LBound(T, 2) To UBound(T, 2)
If CDate(T(i, j)) < Date - 15 Then T(i, j) = ""
Next j
Next i
Plg = T
End Sub