Private Sub Worksheet_Change(ByVal Target As Range)

 Set w = ActiveSheet.Range("J4:L4")

 For Each C In w

 If C.Value <> "" And Not IsDate(C) Then
 C.ClearContents

 MsgBox "Only a Date is permitted in this cell."
 End If

 If C.Value = "" And Not IsDate(C) Then
 C.Interior.ColorIndex = 0
 Else
 C.Interior.ColorIndex = 4
 End If

 Next C

End Sub

Sub CopyLastCell()
Range("J4").End(xlToRight).Copy
Range("M4").PasteSpecial

Application.CutCopyMode = False
End Sub