Airframe's Date of Manufacture
Ladies and gentlemen, looking for a definitive answer to the following query. It relates to Aircraft Manufacture Dates. On inspecting an aircraft's cn/msn plate, a "mfg date" is often quoted. Obviously it takes many weeks to build an aircraft, so what is considered when determining a particular airframe's date of manufacture? Secondly has the EC, perhaps through EASA, stipulated a common policy for determining this date in relation to airframes built within the EU? Many thanks in advance.