def add_update_date(self, item):
        """ All item['updated_on'] from perceval is epoch """
        updated = unixtime_to_datetime(item['updated_on'])
        timestamp = unixtime_to_datetime(item['timestamp'])
        item['metadata__updated_on'] = updated.isoformat()
        # Also add timestamp used in incremental enrichment
        item['metadata__timestamp'] = timestamp.isoformat()
All item['updated_on'] from perceval is epoch