Const PWD = "222"

Sub Worksheet_activate()
  Me.Protect Password:=PWD, UserInterfaceOnly:=1
End Sub

Private Sub Worksheet_Change(ByVal Target As Range)
Worksheet_activate
Dim col As Long: col = Target.Column
If Target.Count > 1 Then Exit Sub
If Intersect(Range("P8:SZ9,P63:SZ64,P67:SZ68"), Target) Is Nothing Then Exit Sub
Application.ScreenUpdating = False
Application.EnableEvents = False
If Cells(8, col) <> "" And Cells(9, col) <> "" And _
Cells(63, col) <> "" And Cells(64, col) <> "" Then
Cells(65, col) = Date
Else
Cells(65, col) = ""
End If
If Cells(8, col) <> "" And Cells(9, col) <> "" And _
Cells(67, col) <> "" And Cells(68, col) <> "" Then
Cells(66, col) = Date
Else
Cells(66, col) = ""
End If
Application.EnableEvents = True
Application.ScreenUpdating = True
End Sub