With respect to a worker whom, at the time this Ministerial Ordinance comes into effect, an employer has arranged to have work pursuant to the provisions of Article 25-2, paragraph (2) of the Ordinance for Enforcement of the Labor Standards Act prior to the amendment by this Ministerial Ordinance (hereinafter referred to as the "former Rules"), with respect to the working hours pertaining to the period of an agreement, etc. under the former Rules that includes March 31, 2001, from among the fixed periods of not more than one month specified by an agreement based on the provisions of that paragraph or by the rules of employment or an equivalent instrument, or the settlement periods referred to in item (ii) of Article 25-2, paragraph (3) of the former Rules specified by an agreement based on the provisions of that paragraph or by an agreement, the provisions then in force continue to govern, notwithstanding the provisions of Article 25-2, paragraphs (2) and (3) of the new Rules.