A motion to quash provides the trial court with the opportunity to determine whether documents should be produced pursuant to the underlying subpoena. If the motion to quash is granted, then the documents remain in the custody of the person subpoenaed and are not used in the litigation. The process is particularly important when dealing with presumptively privileged documents--such as the hospital records here. (See Evid. Code, 994 physician-patient privilege.) Often the subpoena recipient does not have sufficient self-interest to object to production so the motion to quash allows a party to bring the privilege or other evidentiary objection to the attention of the court. (M. B. v. Superior Court (2002) 103 Cal.App.4th 1384, 1392.) A motion to quash is typically filed before the time for production (see, e.g., Code Civ. Proc., 1985.3, subd. (g)), but the court has authority to consider the motion even if brought after the date for production. (Slagle v. Superior Court (1989) 211 Cal.App.3d 1309, 1312-1313.)