The regulations, limitations and restrictions of this chapter may from time to time be amended, changed, modified or repealed, and the boundaries of the districts hereby established may be changed by an ordinance adopted by the Borough Council; but no amendment for change shall become effective unless the ordinance proposing the amendment or change shall first have been submitted to the Planning Board for approval, disapproval or suggestions. The Planning Board shall have a reasonable time, but not less than 30 days, for consideration and report. In the case of an unfavorable report by the Planning Board, the amendment shall not become effective, except by a favorable vote of 2/3 of the Borough Council.