California Code, Financial Code - FIN § 14352

For purposes of the annual assessment, the total assets of a credit union holding a certificate authorizing it to act as a credit union shall be determined as of a date fixed by the commissioner.  However, if a credit union does not hold a certificate authorizing it to act as a credit union as of that date but does so as of the date when the annual assessment is levied, its total assets for purposes of the annual assessment shall be determined as of the date of the levy.