S.D. Codified Laws § 27A-12-27.2
If a person is subject to a petition for involuntary commitment under this title, the inpatient facility may detain that person in the facility for a period of time not to exceed four hours after the time set for discharge, if necessary for a law enforcement official or agency to obtain custody of the person. This period of time includes four hours after the board of mental illness releases a detention of the person pursuant to this title. If the person is not taken into custody after the notice to the requester and within the specified period of time, the person shall be released from any detention or discharged, as appropriate. The inpatient facility shall record the time of the release or discharge in the person's medical record. If the person was a voluntary patient in the inpatient facility, the person shall maintain the right to discharge as provided in § 27A-8-10.
SDCL 27A-12-27.2