S.D. Codified Laws § 23A-35A-10

No order entered under this section may authorize the interception of any wire, electronic, or oral communication for any period longer than is necessary to achieve the objective of the authorization, in any event no longer than thirty days. Any extension of any order may be granted, but only upon application for an extension made in accordance with § 23A-35A-4 and the judge makes the required findings pursuant to § 23A-35A-6. The period of extension may not be longer than the authorizing judge deems necessary to achieve the purposes for which the extension was granted and in no event for longer than thirty days.