Does the Attorney General have any authority to pass on the starting date for credit under section 2900.5 and section 2933.1?

Defendant was awarded credit for 161actual days of presentence custody, plus 24 days of good time credits, for a total of 185 days of credit. He contends that he is in fact entitled to credit for163 actual days plus 24 days of good time credits, for a total of 187 days of credit. The Attorney General argues that defendant has not carried his burden of establishing that the number awarded is incorrect, suggesting that there may be a difference between the date defendant was arrested and the date he was jailed. The Attorney General acknowledges that there is conflicting authority as to whether the contention is forfeited for failure to have objected in the trial court, and as to which date starts the calculation of credits under sections 2900.5 and 2933.1. We do not believe the contention has been forfeited (People v. Johnson (2007) 150 Cal.App.4th 1467, 1485), and it is unnecessary to pass on the correct starting date because the record discloses that defendant was jailed on the date of his arrest.