On Error GoTo son
    
    With Metin0
      If .Value = "" Then GoTo enson
    Dim tarih As Variant, trh As Date, eom As Long, deger As String

          .Value = Replace(.Value, " ", ".")
          .Value = Replace(.Value, "/", ".")
          tarih = Split(.Value, ".")
          If Len(tarih(0)) = 1 Then tarih(0) = "0" & tarih(0)
          If Len(tarih(1)) = 1 Then tarih(1) = "0" & tarih(1)
          deger = tarih(0) & "." & tarih(1) & "." & tarih(2)
          If Not deger Like "##.##.####" Then
              MsgBox "Tarih bilgisi ""gg.aa.yyyy"" þeklinde girilmelidir.", vbCritical, "HATA"
              .SetFocus
              GoTo var
          Else
          
              trh = DateSerial(tarih(2), tarih(1), 1)
              eom = Day(CLng(DateSerial(Year(trh), Month(trh) + 1, 0)))
              If Val(tarih(0)) > eom Then
                  GoTo son
                  .SetFocus
              End If
              If tarih(1) > 12 Then
                  GoTo son
                  .SetFocus
              End If
          End If
    
    
var:
    eom = Empty: trh = Empty: deger = Empty: Erase tarih
Exit Sub
son:
      .SetFocus
      MsgBox "Hatali Tarih...", vbCritical, "Hata"
      Cancel = True
    Exit Sub
enson:
End With