Section 26-18-105 - Date of performance(a)(1) If any return, claim, statement, or other document required to be filed within a prescribed period or on or before a prescribed date under any state tax law is, after that period or date, delivered by the United States mail to the Secretary of the Department of Finance and Administration or to the Tax Appeals Commission, the date of the United States postmark stamped on the cover of the return, claim, statement, or other document shall be deemed to be the date of delivery.(2) Only the postmark of the United States Postal Service, rather than those of private postage meters, shall qualify for the provisions of this section.(b) When the last day prescribed under the authority of state tax laws for performing any act or instituting any suit falls on Saturday, Sunday, or a legal holiday, the performance of the act shall be considered timely if it is performed on the next succeeding business day which is not a Saturday, Sunday, or legal holiday.Amended by Act 2023, No. 251,§ 1, eff. 3/9/2023.Acts 1979, No. 401, § 27; A.S.A. 1947, § 84-4727. See Act 2023, No. 251, § 2.