The amendment to Penal Code section 4019 granting more presentence good conduct credit applies prospectively only. Appellant was sentenced in February, 2009, to three years eight months in prison and was awarded presentence credits of 380 days. In January, 2010, the Legislature amended section 4019 to provide that specified persons may accrue conduct credit at the rate of four days for every four days of presentence custody. The statute did not specify that it had prospective application only. Appellant contended on appeal that the 2010 amendment to section 4019 was retroactive, and therefore the more generous conduct credit accrual provisions applied to him. The appellate court disagreed, finding that revised Penal Code section 4019 does not apply retroactively, and that application of the amendment in a prospective manner does not violate equal protection.