Conduct credits against a defendant’s prison sentence attributable to a jail term served as a condition of probation are subject to the 15% limitation of Penal Code section 2933.1. Initially, imposition of sentence was suspended, and probation granted. Even though defendant received credits on his one-year conditional jail term under Penal Code section 4019 for time in custody before probation was granted and while he was in jail, once probation was revoked and he was sentenced to prison, the actual custody time was subject to the 15% limitation.