(a) As used in this article:
(1) “State-aided district” means a district to which a conditional or final apportionment has been made under this chapter.
(2) “Acquiring district” means a district in which all, or a part of, a state-aided district or an applicant district has been included.
(b) Except as otherwise provided in Section 15788, the effective date for the purposes of this article of any change of boundaries or annexation or other inclusion affecting a school district shall be the date the action became effective for the purposes of Section 4002.