An act is timely if:
(1) the last day for the performance of the act is:
(A) a Saturday, Sunday, or legal state or national holiday; or
(B) in the case of a payment of taxes imposed by a taxing unit, a day on which the office of the collector for the taxing unit is closed; and
(2) the act is performed on the next regular business day.
Official text of the Texas Tax Code as published by the Texas Legislative Council.