The expiration date of your visa is the last day you may use the visa to enter the United States. It does not indicate how long you may stay in the United States. Your stay is determined by the Department of Homeland Security at your port of entry.
In some circumstances, a person may be released from custody without bail and be given an order to appear, with certain conditions as governed and directed by a court-affiliated agency. Project Remand ('PR'), a Ramsey County pre-trial court service program, is one example of such an agency.
The bail agent, the defendant, or another interested party posts bail in the form of the bail bond at the court where the defendant is required to return for the proceeding. The court clerk issues a bail ticket or similar document, which is sent to the police to notify them that bail has been met.