I discussed this briefly with some Swedish mappers and one suggested that you may treat the parking lot as unsigned on weekends, since none of the signs would apply, but we're not really sure. Your propsed tagging seems correct, if time slots indicate only weekdays in OSM too. Maybe add permissive access during weekends to convey the ambiguity of the sign? Or simply access=no to discourage parking when you might get a fine. I leave that decision to you :)