So if an airfield has published hours of 8am to 8pm but NOTAMs a closure between 1pm and 2pm can you land at a private site within the area of the ATZ without ATC permission (because there is no ATZ/ATC active)?
Remember you only require ATC permission if it is a Control Zone. A normal ATZ that is air / ground or "radio Information" has no authority and only supplies or asks for information ...