I'm probably wrong but I believe that landing at an unlicenced field means you are fully responsible in case of an accident. If you land at a licenced a/field before its official licenced hours begin, you will be frowned upon because they are not licenced out of hours.
I once landed at an airfield not far from Boscombe before they opened (8.55 am) and all hell let lose because they were not licenced before 9 am. Muchos apologies to all and I was forgiven though.