
561 S.W.2d 798 (1977)
N-S-W CORPORATION, Relator,
v.
Honorable John SNELL, Jr., et al., Respondents.
No. B-6967.
Supreme Court of Texas.
December 14, 1977.
Cox, Pakenham & Roady, Joe G. Roady, Houston, for relator.
J. Donald Bowen, Houston, for respondents.
POPE, Justice.
N-S-W Corporation seeks a mandamus ordering the trial judge to set aside an order that reinstated a cause upon the docket. It insists the order is void since the judge ordered the reinstatement more than thirty days after the date of its dismissal order and after the court had lost jurisdiction over its prior order. We conditionally grant the writ of mandamus.
H. R. George Gwyn, III sued N-S-W Corporation for damages for breach of a contract. On May 5, 1977, the trial court dismissed the action for want of prosecution. On May 25, Gwyn filed his motion to reinstate the cause. Under those facts it was necessary for the trial court to order the reinstatement within thirty days after May 5, which would have been by June 4, 1977. Rule 165a, Tex.R.Civ.P. That date was a Saturday, so the following Monday, June 6, 1977, is our critical date. Rule 4. The dispute before us is whether the trial judge rendered a judgment for reinstatement on June 6, which would be the last day within the thirty days during which the court still retained jurisdiction. Conclusive evidence of the date of the order is contained in the order of reinstatement:
On this the 13th day of June, 1977, came on to be heard Plaintiff's Motion to Reinstate a Case on the Docket of the Court, and the Court having duly heard and considered same, is of the opinion that such motion should be and is in all things granted, it is, therefore
ORDERED that the above entitled and numbered cause be reinstated on the docket of this Court, to have the same status as before the call of the dismissal docket.
SIGNED AND ENTERED this 11th day of July, 1977.
               /s/ Peter S. Solito  
             John Snell, Jr.,
               Judge Presiding
Respondent Gwyn says that the recital that the order came on for hearing on June 13 is brought in question by this entry on the docket sheet:
*799
                              granted
  "June 6-1977 M to reinstate denied as per order"
Respondent Gwyn says that the word "denied" was stricken on June 6, at which time the judge actually granted the motion to reinstate. Relator, N-S-W Corporation on the other hand, says that the trial judge changed the order after June 6, but, in any event, the docket entry may not impeach the court's order.
A docket entry may supply facts in certain situations, Matthews v. Looney, 132 Tex. 313, 123 S.W.2d 871 (1939), but it cannot be used to contradict or prevail over a final judicial order. Hamilton v. Empire Gas & Fuel Co., 134 Tex. 377, 110 S.W.2d 561 (1937); Ex parte Rains, 113 Tex. 428, 433, 257 S.W. 217, 220 (1923); Stark v. Miller, 63 Tex. 164 (1885).
We accordingly grant the prayer for a mandamus ordering the vacation of the July 11 order. Judge John Snell, Jr., who heard the motion, is now deceased, and this mandamus is directed to his successor in office. The writ of mandamus will issue only in the event the reinstatement order is not vacated.
