13. Any alteration in the valuation list made in consequence of Article 5(1) of the Rates Amendment (Northern Ireland) Order 1977 [1977 NI 9] or Article 41(5) may be treated for the purpose of levying a rate for the year ended on 31st March 1977 as having had effect from the beginning of that year or from such later date as is appropriate in all the circumstances; and, for the purpose of determining what (if any) later date is appropriate, paragraphs (2) to (6) of Article 13 shall apply (and consequently Articles 11(2)( a) and 32(7)( b) shall have effect) as if the reference in Article 13(2) to Article 13(1)( f)(ii) included a reference to this paragraph.