This is an appeal from a judgment dismissing plaintiffs’ cause of action1 entered pursuant to an order granting defendants’ motion for summary judg*550ment. The motion was made under Rule 56, Rules of Civil Procedure. However, the notice of motion was admittedly not served upon plaintiffs the full 10 days prior to the return date and hearing thereon.2 Because we hold that the stated time for notice is mandatory, absent a clear waiver by the adversary, the judgment must be reversed.
Defendants are a school district and members of its board of education, and plaintiffs are dissident voters and taxpayers. On April 19, 1963, defendants conducted an election for authorization to issue $125,000 in school building bonds, and the voters duly approved it. On January 22, 1965, the validity of this election was upheld in Lindahl v. Independent School Dist. No. 306, 270 Minn. 164, 133 N. W. (2d) 23. On June 17, 1965, plaintiffs petitioned defendant board to conduct an election to rescind its prior proceedings. At a special meeting on July 1, 1965, the board “tabled” the petition and resolved, instead, for the calling of a bond sale on July 22, 1965. On July 21, 1965, plaintiffs obtained a temporary restraining order against the bond sale and the making of any contracts for construction of the proposed school building. The complaint and order to show cause were served upon defendants on July 21, 1965, and the order for hearing on plaintiffs’ motion for a temporary injunction was made returnable August 24, 1965.
Defendants mailed their notice of motion for summary judgment to plaintiffs on August 17, 1965, the notice stating that the hearing on the motion would be had on August 24, 1965.3 The time of service fell 5 days short of the time required by the Rules of Civil Procedure.4
Defendants urge that, notwithstanding the admitted untimeliness of their motion for summary judgment, it qualified as a timely motion for judgment *551on the pleadings pursuant to Rule 12. They assert that both court and counsel so treated it and that “this is what the order was intended to be.” This is disputed by plaintiffs, at least with respect to their position. That the trial court treated the motion as one for summary judgment under Rule 56 is plain both from its order 5 and from the judgment6 itself.
The trial court, moreover, considered matters outside the pleadings, thus making it necessary to treat the motion as one for summary judgment under Rule 56.7 Three lengthy affidavits, together with numerous incorporated documents, were presented to the trial court and cover more than half the printed record. An affidavit of defendants’ attorney and bond consultant was specifically directed and relevant to their motion to require plaintiffs to file a surety bond. However, an affidavit of defendants’ superintendent of schools was unrestricted and relevant mainly to the merits of the action itself. An' “affidavit of merit and reply” by plaintiffs was by its terms “a reply to the Answer” of defendants, quite obviously filed to support plaintiffs’ own motion for a temporary injunction.
Defendants further urge that no objection was made by plaintiffs to *552hearing defendants’ motion and that, therefore, this objection was waived. Plaintiffs deny this, asserting that the hearing of defendants’ motion was vigorously protested and claiming that plaintiffs had other evidence to submit. They were of course present at the hearing in support of their own motion for a temporary injunction, duly noticed for that date. There is nothing in the record indicating their consent to a hearing upon any other motion. Plaintiffs’ affidavit of merit and reply in support of their own motion falls short of constituting a waiver of objection to the timeliness of a motion for summary judgment.8
Although the Rules of Civil Procedure are to be construed to secure a just, speedy, and inexpensive determination of actions,9 any other result would in this case equally thwart the clear mandate of Rule 56.03 under the guise of construction. Our opinion that the motion, order, and judgment herein were fatally defective for want of timeliness does not intimate either that plaintiffs’ pleadings are beyond successful attack by appropriate motions or that a temporary injunction should necessarily have issued on their own pending motion. We hold only that plaintiffs were in this instance denied their day in court.
Reversed.