All determinations so made, exclusive of penalties, shall bear interest at the modified adjusted rate per month, or fraction thereof, established pursuant to Section 6591.5, from the last day of the month after the close of the monthly period for which the amount or any portion thereof should have been returned until the date of payment.
(Repealed and added by Stats. 2000, Ch. 1053, Sec. 12. Effective January 1, 2001. Operative January 1, 2002, by Sec. 53 of Ch. 1053.)