This is an application  for certiorari  which presents  the question of whether the order of the Public Service Commission which  is challenged was  without the jurisdiction of the  commission.  This  question,  in turn,  requires  a ruling on the question raised by the petitioner as to when a decision of the Public Service Commission becomes final.

The petitioner herein,  the Rural Transit Company,  filed with the Public Service  Commission  on August  30, 1929, an  application  for a certificate of  public  convenience. Written oppositions were interposed by several parties, among whom was Pedro Sumaquiao.   The case was heard on  November  22,  1929,  without the  presence  of either Pedro Sumaquiao or his attorney.  Accordingly, on May 31, 1930,  the  associate  commissioner  rendered his  decision granting the application for the lines applied for.  In the decision there  was a provision to  the effect that the same  should become final thirty days after the notification of the parties.   Notice of the decision was  served on all the parties, including  Pedro Sumaquiao, on June 5, 1930. After the expiration of the thirty-day period, or to be exact, on  July 11,  1930,  Pedro Sumaquiao  filed a  motion for rehearing.  Opposition to this motion Was  registered by the Rural Transit Company, but  the same was granted by the associate  commissioner in  an order of  October  9, 1930,  which suspended the effects of the decision previously promulgated.   A motion for reconsideration presented on behalf of the  Rural Transit  Company was  denied, after which it was requested that it be decided, if the decision of the associate  commissioner was  final,  when  the motion for rehearing was filed.  When the commissioner sustained his authority in the premises, these certiorari  proceedings were  initiated.

Section 35 of the Public  Service Law, Act No. 3108, as amended, provides  that  "Any order made by the commission may be reviewed  on the application of any  person or public service affected  thereby, by certiorari in appropriate cases, or by petition, to  the Supreme Court, within thirty days  from the  date upon which such order becomes effective."  Section 28  of the same law further  provides  that "The Commission, at any time,  may order a rehearing to extend,  revoke, or modify any order made by  it.   Once a case has been decided after the rehearing, any interested party may, if he so desires, take an appeal to the Supreme Court by following the procedure prescribed  in  section thirty-five of this Act,  *  *  *."  In actual practice also, the commission, pursuant to its rule making power, inserts a proviso such as is to be found in the decision in this case, making the decision final after thirty days for the purposes of appeal.

The facts not being in dispute, and  the applicable law being known, we address attention to the question suggested in the beginning of this opinion.  We  note no vagueness in the law.  We experience no hesitancy in announcing the rule which  should  be followed.   Frankly  speaking,  what is the use in debating the question whether a motion for rehearing was filed in time,  when the law gives the Public Service  Commission full power  to grant  a  rehearing at any time?

To elucidate further, let us suppose, as in this case, that notice of the decision was served on the parties  on June 5, 1930.  Under the law and pursuant to recognized practice, the losing party had thirty days within which to file  a motion  for reconsideration and  within  which to take the necessary steps to elevate the case to the Supreme Court by certiorari or petition for review.  After the expiration of that thirty-day period, the decision would become final and unappealable.   But at any  time,  for instance  as  in this case on  July 11, 1930, or six days after the decision  became final, for the purposes of appeal, the  commission could legally order a rehearing on  any order made  by it.  It is, therefore, perfectly  clear that the decisions or orders of the Public Service Commission  become final  after thirty days not in  the sense that it loses control over the same to revive them  for the purpose either of extending, revoking, or  modifying them, but in the sense that no appeal therefrom may be taken to the Supreme Court.

We  hold that  the  Public Service  Commissioner  acted properly in the exercise of  discretionary jurisdiction  expressly conferred by law upon the Public Service Commission in granting  the  motion for  rehearing.   Accordingly, the application will be denied, with the costs of this instance against the petitioner.

Avanceña, C. J., Johnson, Street, Villamor, Ostrand, Romualdez, Villa-Real, and Imperial, JJ., concur.