Cal. FAM § 2346

(a) If the court determines that a judgment of dissolution of the marriage should be granted, but by mistake, negligence, or inadvertence, the judgment has not been signed, filed, and entered, the court may cause the judgment to be signed, dated, filed, and entered in the proceeding as of the date when the judgment could have been signed, dated, filed, and entered originally, if it appears to the satisfaction of the court that no appeal is to be taken in the proceeding or motion made for a new trial, to annul or set aside the judgment, or for relief under Chapter 8 (commencing with Section 469) of Title 6 of Part 2 of the Code of Civil Procedure.

(b) The court may act under subdivision (a) on its own motion or upon the motion of either party to the proceeding. In contested cases, the motion of a party shall be with notice to the other party.

(c) The court may cause the judgment to be entered nunc pro tunc as provided in this section, even though the judgment may have been previously entered, where through mistake, negligence, or inadvertence the judgment was not entered as soon as it could have been entered under the law if applied for.

(d) The court shall not cause a judgment to be entered nunc pro tunc as provided in this section as of a date before trial in the matter, before the date of an uncontested judgment hearing in the matter, or before the date of submission to the court of an application for judgment on affidavit pursuant to Section 2336. Upon the entry of the judgment, the parties have the same rights with regard to the dissolution of marriage becoming final on the date that it would have become final had the judgment been entered upon the date when it could have been originally entered.