Cal. Rev. & Tax. Code § 19101
(b) For purposes of this article, the last date prescribed for payment of the tax shall be determined under Chapter 4 (commencing with Section 19001), with the application of the following rules:
(c) Except as provided in this article:
(2)
(B) Interest shall be imposed under this article with respect to any addition to tax imposed by Section 19131 (relating to failure to file a return on or before the due date), Section 19132 (relating to underpayment of tax), or Section 19164 (relating to imposition of the accuracy-related penalty), for the period that: