S.D. Codified Laws § 9-8-8
The council holds its regular meetings on the first Monday of each month but may, by ordinance, change the day of its regular monthly meetings. The council may prescribe by ordinance the manner in which special meetings may be called.
A majority of the aldermen constitutes a quorum to do business. When a seat on a council is vacant due to removal, resignation, death, or by operation of law, the quorum consists of the majority of the remaining aldermen who are qualified to serve as aldermen by election or appointment pursuant to chapter 9-13. The council may compel the attendance of absentees under such penalties as may be prescribed by ordinance.
The meetings of the council are open to the public and it shall keep a journal of its proceedings.
SDCL 9-8-8