Cal. Educ. Code § 15781

When a district has received conditional apportionments which have become final under this chapter, and there is a unification of the district prior to December 31, 1952, within the meaning of Section 4320, with another district having the same boundaries, the effective date of the unification for the purpose of the first district receiving additional apportionments pursuant to the terms of Section 15714 shall be July 1, 1953.