In all Commercial and Manufacturing Districts, the Board of Standards and Appeals may permit a reduction in the number of accessory off-street parking spaces required under the provisions of Sections 25-31, 36-21 or 44-21 (General Provisions) for uses in parking requirement category D (Places of Assembly) whenever such uses are located on the same zoning lot as other uses, proportionate to the extent that the Board finds:

(a)        that the spaces accessory to such other uses will remain available for use by persons visiting the place of assembly during the entire period that such place of assembly remains in use; and

(b)        that, in accordance with submitted schedules of the times of operation for all uses on the zoning lot, there will be no conflict in the use of such accessory off-street parking spaces, and that the provision of the full quota of required off-street parking spaces for places of assembly is therefore not needed. The permit to reduce such spaces shall be automatically revoked whenever there is a change in the nature of the conditions upon which such reduced requirements were based, including changes in use, availability of spaces or hours of operation.