Minn. Stat. § 645.151: TIMELY DELIVERY OR FILING.

When an application, payment, return, claim, statement, or other document is to be delivered to or filed with a department, agency, or instrumentality of this state or of a political subdivision on or before a prescribed date and the prescribed date falls on a Saturday, Sunday, or legal holiday, it is timely delivered or filed if it is delivered or filed on the next succeeding day which is not a Saturday, Sunday, or legal holiday.