Tex. R. Civ. P. 5

When by these rules or by a notice given thereunder or by order of court an act is required or

allowed to be done at or within a specified time, the court for cause shown may, at any time in its

discretion (a) with or without motion or notice, order the period enlarged if application therefor is

made before the expiration of the period originally prescribed or as extended by a previous order;

or (b) upon motion permit the act to be done after the expiration of the specified period where good

cause is shown for the failure to act. The court may not enlarge the period for taking any action

under the rules relating to new trials except as stated in these rules. If any document is sent to the

proper clerk by first-class United States mail in an envelope or wrapper properly addressed and

stamped and is deposited in the mail on or before the last day for filing same, the same, if received

by the clerk not more than ten days tardily, shall be filed by the clerk and be deemed filed in time.

A legible postmark affixed by the United States Postal Service shall be prima facie evidence of the

date of mailing.