Is a defendant entitled to credit for his time served in custody?

Defendants who have been in custody during the pendency of their charges are entitled to receive credit against their sentence for days served in connection with the charged conduct. ( 2900.5, subd. (a); People v. Buckhalter (2001) 26 Cal.4th 20, 30.) The trial court has a duty to determine the amount of time served and the total number of custody credits to which a defendant is entitled. ( 2900.5, subd. (d); People v. Buckhalter, supra, 26 Cal.4th at p. 30.) Defendants contend, and the Attorney General does not dispute, that the trial court did not perform that duty here. Indeed, the transcript of the sentencing hearing and the abstracts of judgment indicate that neither defendant received any custody credit. (See 2900.5, subd. (d) ["The total number of days to be credited shall be contained in the abstract of judgment"].)