Any area that is designated attainment or unclassifiable for carbon monoxide under section
of this title, and that is subsequently redesignated to nonattainment for carbon monoxide under section
of this title, shall, at the time of the redesignation, be classified by operation of law in accordance with table 1 under subsections (a)(1) and (a)(4) of this section. Upon its classification, the area shall be subject to the same requirements under section
of this title, subpart 1 of this part, and this subpart that would have applied had the area been so classified at the time of the notice under subsection (a)(2) of this section, except that any absolute, fixed date applicable in connection with any such requirement is extended by operation of law by a period equal to the length of time between November 15, 1990, and the date the area is classified.