In In re Estrada (1965) 63 Cal.2d 740, the court concluded that if the Legislature amends a statute to mitigate the punishment for a specific crime, it must be assumed that the Legislature intended that the statute be retroactively applied to all defendants whose judgments of conviction were not final at the time of the statute's operative date if there is no other evidence to the contrary. (Id. at pp. 742-748.) The rule derived from Estrada is not without limits. Section 3 specifies that "no part of the Penal Code is retroactive, unless expressly so declared." Thus, while Estrada certainly operates to determine if a statute should be retroactively or prospectively applied, section 3 is also still applicable such that "in the absence of an express retroactivity provision, a statute will not be applied retroactively unless it is very clear from extrinsic sources that the Legislature . . . must have intended a retroactive application." (Evangelatos v. Superior Court (1988) 44 Cal.3d 1188, 1209.) Put in other words, the Estrada holding applies in situations where "the amendatory statute mitigates punishment and there is no savings clause." (Estrada, supra, 63 Cal.2d at p. 748.) As the California Supreme Court in People v. Brown (2012) 54 Cal.4th 314, 323 surmised, "Estrada is today properly understood, not as weakening or modifying the default rule of prospective operation codified in section 3, but rather as informing the rule's application in a specific context by articulating the reasonable presumption that a legislative act mitigating the punishment for a particular criminal offense is intended to apply to all nonfinal judgments." (Brown, supra, 54 Cal.4th at p. 324.) In Brown, the California Supreme Court recognized some of the limitations to the applicability of the Estrada rule. The court held that the holding in Estrada did not extend to retroactively apply an increased conduct credit calculation under section 4019 to those defendants whose judgments were not final on the statute's effective date. (Brown, supra, 54 Cal.4th at p. 328.) In Brown, the defendant argued that the Estrada holding should be extended to apply to "any statute that reduces punishment in any manner, and that to increase credits is to reduce punishment." However, the Supreme Court rejected this argument, finding that Estrada is "specifically directed to a statute that represents ' "a legislative mitigation of the penalty for a particular crime" ' (Estrada, 63 Cal.2d at p. 745) because such a law supports the inference that the Legislature would prefer to impose the new, shorter penalty rather than to ' "satisfy a desire for vengeance." ' " (Id. at p. 325.) The court concluded that this logic did not extend to a law that rewards a prisoner's good conduct while incarcerated. (Ibid.)