SDCL § 12-1-17: Computation of time allowed for election notice or filing.

In computing any period of time prescribed or allowed for an election notice or filing, the day of the act or event from which the designated period of time begins to run is not included. The last day of the period so computed shall be included, unless it is a Saturday, a Sunday, or a legal holiday, in which event the period runs until 5:00 p.m. on the next day which is not a Saturday, a Sunday, or a legal holiday. If the period of time prescribed or allowed is less than seven days, intermediate Saturdays, Sundays, and legal holidays shall be excluded in the computation.