(a)Grounds. A new trial or rehearing may be granted to all or any of the parties and on all or part of the issues
(1) in an action in which there has been a trial by jury, for any of the reasons for which new trials have heretofore been granted in actions at law in the courts of the United States; and
(2) in an action tried without a jury or in an action finally determined, for any of the reasons for which rehearings have heretofore been granted in suits in equity in the courts of the United States. On a motion for a new trial in an action tried without a jury, the court may open the judgment if one has been entered, take additional testimony, amend findings of fact and conclusions of law or make new findings and conclusions, and direct the entry of a new judgment.
(b)Time for Motion. A motion for a new trial or rehearing shall be served and filed not later than 30 days after the entry of the judgment or order.
(c)Time for Serving Affidavits. When a motion for a new trial or rehearing is based upon affidavits they shall be served with the motion. The opposing party has 10 days after such service within which to serve opposing affidavits, which period may be extended for an additional period not exceeding 20 days by order of the court for good cause shown or by the parties by written stipulation. The court may permit reply affidavits.
(d)On Court’s Initiative. Not later than 30 days after the entry of judgment or order the court on its own initiative may order a new trial or rehearing for any reason that would justify granting one on a party’s motion. After giving the parties notice and an opportunity to be heard on the matter, the court may grant a motion for a new trial or rehearing, timely served, for a reason not stated in the motion. When granting a new trial on its own initiative or for a reason not stated in a motion, the court shall specify the grounds in its order.
(e)Motion To Alter or Amend a Judgment. A motion to alter or amend a judgment shall be served not later than 30 days after the entry of the judgment.