In Stone v. Regents of University of California (1999) 77 Cal.App.4th 736, the court looked to whether the change was a clerical one, as opposed to change that "was material and substantial. 'If a party can obtain the desired relief from a judgment before it is amended, he must act -- appeal therefrom -- within the time allowed after its entry. If the amendment materially and in a substantial respect affects the judgment and the rights of a party against whom it is rendered, and a party desires relief therefrom, he must appeal from the corrected judgment.' Changes which correct errors, mistakes and omissions made through inadvertence, but do not involve the exercise of the judicial function, are considered corrections of clerical errors that leave the original judgment intact." (Ibid.) In Stone, the court concluded that an appeal of the underlying judgment was timely, where an amendment or modification order had required the defendants to pay an additional nine months' worth of defense costs, and it thus materially affected their rights. (Id. at pp. 743-744.)