Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Address = "$B$1" Then
ActiveSheet.Columns.Hidden = False
x = Month(DateValue("01/" & Target))
Range(Cells(1, x + 2), Cells(1, 13)).EntireColumn.Hidden = True
Range(Cells(1, x + 16), Cells(1, 27)).EntireColumn.Hidden = True
End If
End Sub