Cal. Rev. & Tax. Code § 18155.5

Section 1223 of the Internal Revenue Code, relating to holding period of property, is modified to additionally provide that in determining the period for which the taxpayer has held property the acquisition of which resulted under Section 18038.5 in the nonrecognition of any part of the gain realized on the sale of other property, there shall be included the period for which that other property has been held as of the date of the sale.