Wis. Stat. § 809.82: Rule (Computation and enlargement of time).

(1) Computation. In computing any period of time prescribed by these rules, the provisions of s. 801.15 (1) and (5) apply.

(2) Enlargement or reduction of time.

(a) Except as provided in this subsection, the court upon its own motion or upon good cause shown by motion, may enlarge or reduce the time prescribed by these rules or court order for doing any act, or waive or permit an act to be done after the expiration of the prescribed time.

(b) Notwithstanding par. (a), the time for filing a notice of appeal or cross-appeal of a final judgment or order, other than in an appeal under s. 809.107 or an appeal under s. 809.30 or 809.32, may not be enlarged.

(c) The court may not enlarge the time prescribed for an appeal under s. 809.105 without the consent of the minor and her counsel.

(e) Notwithstanding par. (a), the time for filing a motion for reconsideration under s. 809.24 may not be enlarged.