Aktif sayfa ve hedef hücrelerde tarih formatı
Private Sub Worksheet_Change(ByVal Target As Excel.Range)
Dim DateStr As String
On Error GoTo EndMacro
If Application.Intersect(Target, Range("A1:A10")) Is Nothing Then
    Exit Sub
End If
If Target.Cells.Count > 1 Then
    Exit Sub
End If
If Target.Value = "" Then
    Exit Sub
End If
Application.EnableEvents = False
With Target
If .HasFormula = False Then
    Select Case Len(.Formula)
        Case 4 ' e.g., 9298 = 2-Sep-1998
            DateStr = Left(.Formula, 1) & "/" & _
            Mid(.Formula, 2, 1) & "/" & Right(.Formula, 2)
        Case 5 ' e.g., 11298 = 12-Jan-1998 NOT 2-Nov-1998
            DateStr = Left(.Formula, 1) & "/" & _
                Mid(.Formula, 2, 2) & "/" & Right(.Formula, 2)
        Case 6 ' e.g., 090298 = 2-Sep-1998
            DateStr = Left(.Formula, 2) & "/" & _
                Mid(.Formula, 3, 2) & "/" & Right(.Formula, 2)
        Case 7 ' e.g., 1231998 = 23-Jan-1998 NOT 3-Dec-1998
            DateStr = Left(.Formula, 1) & "/" & _
                Mid(.Formula, 2, 2) & "/" & Right(.Formula, 4)
        Case 8 ' e.g., 09021998 = 2-Sep-1998
            DateStr = Left(.Formula, 2) & "/" & _
                Mid(.Formula, 3, 2) & "/" & Right(.Formula, 4)
        Case Else
            Err.Raise 0
    End Select
    .Formula = DateValue(DateStr)
End If
End With
Application.EnableEvents = True
Exit Sub
EndMacro:
MsgBox "You did not enter a valid date."
Application.EnableEvents = True
End Sub