Private Sub Worksheet_Change(ByVal Target As Range)
Dim s As String
Dim j As String, m As String, a As String
If Target.Count > 1 Then Exit Sub
Application.EnableEvents = False
Target.NumberFormat = "@"
Application.EnableEvents = True
s = Format(Target.Value, "00000000")
If Len(s) <> 8 Then Exit Sub
j = Left(s, 2)
m = Mid(s, 3, 2)
a = Right(s, 4)
Application.EnableEvents = False
Target.Value = j & "/" & m & "/" & a
Application.EnableEvents = True
End Sub