40Time of importation of goods and time of arrival of ships defined.
If upon the first levying or repealing of any duty, or the first permitting or prohibiting any importation, or at any other time, or for any of the purposes of the Customs Acts, it shall become necessary to determine the precise time at which an importation of any goods shall be deemed to have had effect, such time shall be deemed to be the time at which the ship importing such goods actually came within the limits of the port at which such ship shall in due course be reported and such goods be discharged; and if any question shall arise upon the arrival of any ship in respect of any charge or allowance for such ship, exclusive of cargo, the time of such arrival shall be deemed to be the time at which the report of such ship shall have been or ought to have been made.