What is the effect of section 2900.5 of the California Criminal Code on a defendant who has served time in local jail time as a condition of probation?

Section 2900.5, enacted in 1971 (Stats.1971, ch. 1732, 2, p. 3686), originally established a custody credit scheme for the benefit of defendants who were actually sentenced to state prison.² Although a defendant committed to state prison received credit against his or her prison sentence for any local time spent in jail, including jail time previously served as a condition of probation for the same offense, the credit scheme first embodied in section 2900.5 had no application to defendants who were being sentenced to local jail time as a condition of probation or reinstatement of probation. (See People v. Brasley (1974) 41 Cal.App.3d 311, 314-317, 115 Cal.Rptr. 910 [section 2900.5, as then in effect, applicable only to state prison commitments]; In re Hays (1953) 120 Cal.App.2d 308, 311, 260 P.2d 1030 [no statute then in existence authorized credit against jail sentences for local time previously served as a condition of probation].)