No such amendment, supplement or repeal shall become effective until after a public hearing in relation thereto, at which the parties in interest and citizens of the Incorporated Village of Port Jefferson have an opportunity to be heard in person or by an attorney or duly authorized agent. The Board of Trustees, by resolution at a meeting thereof, shall fix the time and place of the public hearing on the proposed amendment, supplement or change, and at least 15 days' notice of the time and place of such hearing shall be published in the official newspaper.