
251 S.E.2d 647 (1979)
39 N.C. App. 643
STATE of North Carolina
v.
Stephen Louis MOORE.
No. 7824SC839.
Court of Appeals of North Carolina.
February 6, 1979.
*648 Atty. Gen. Rufus L. Edmisten by Associate Attys. J. Chris Prather and Jane Rankin Thompson, Raleigh, for the State.
Triggs & Hodges by C. Gary Triggs, Morganton, for defendant-appellant.
HARRY C. MARTIN, Judge.
Defendant assigns as error the denial of his motion to continue. Continuances of cases are not favored in the law. Chief Justice Sharp, speaking for the Supreme Court in Shankle v. Shankle, 289 N.C. 473, 483, 223 S.E.2d 380, 386 (1976), said:

*649 [B]efore ruling on a motion to continue the judge should hear the evidence pro and con, consider it judicially and then rule with a view to promoting substantial justice. The rule has been well stated as follows:
"In passing on the motion the trial court must pass on the grounds urged in support of it, and also on the question whether the moving party has acted with diligence and in good faith. In reaching its conclusion the court should consider all the facts in evidence, and not act on its own mental impression or facts outside the record, although . . . it may take into consideration facts within its judicial knowledge. . . . The motion should be granted where nothing in the record controverts a sufficient showing made by the moving party, but since motions for continuance are generally addressed to the sound discretion of the trial court . . . a denial of the motion is not an abuse of discretion where the evidence introduced on the motion for a continuance is conflicting or insufficient.. . . The chief consideration to be weighed in passing upon the application is whether the grant or denial of a continuance will be in furtherance of substantial justice." [17 C.J.S. Continuances § 97 (1963).]
Ordinarily, such motions are addressed to the sound discretion of the trial judge and not subject to review absent abuse of discretion. State v. Brower, 289 N.C. 644, 224 S.E.2d 551 (1976). However, in criminal cases constitutional tests may arise on motions for continuance. Where a motion is based upon a right guaranteed by the federal or state constitutions, the question is one of law, and the ruling of the court is one of law and not of discretion and is reviewable on appeal. State v. Harrill, 289 N.C. 186, 221 S.E.2d 325 (1976). Defendant argues the Sixth Amendment rights to production of witnesses and assistance of counsel. Similar provisions are contained in Article I, Sections 19 and 23, of the North Carolina Constitution.
Defendant's counsel filed the motion for continuance immediately after being retained. Defendant's evidence tended to show counsel knew they could not be prepared by the 8 August session of court. It was a period of only seventeen days, including three Saturdays and three Sundays. They had no opportunity to determine whether the State had any discoverable material. The disclosure on the trial date that the State had no such material, except the pistol, came too late to help defendant prepare his defense. Rusher did not communicate with defendant's counsel during this period.
Defendant's evidence tended to show defendant's counsel were unable to secure the attendance of several witnesses they considered material to defendant's defense. One was Susan Westfall, who had lived with defendant for some time. She and defendant had two children. They were not married. Susan had talked to defendant by telephone while the alleged crimes were being committed. About this date Susan had told defendant she was leaving him and taking their children. She had been to North Dakota to her mother's home.
In defendant's motion for continuance, one of the grounds was to secure a psychiatric evaluation of defendant. Defendant's family had a history of mental illness. Defendant had been receiving treatment at the Mental Health Center under Dr. Feldman and counsellor Lennie. The record is not clear whether this was before the alleged crime or after defendant's arrest. In either event, it indicates defendant may have been suffering from some mental or psychiatric condition that could have affected his defense.
The constitutional right to assistance of counsel necessarily includes that counsel should have a reasonable time to prepare for trial. However, no set length of time for investigation, preparation and presentation is required and whether defendant is denied due process must be determined upon the basis of the circumstances in each case. State v. Harris, 290 N.C. *650 681, 228 S.E.2d 437 (1976); State v. Alderman, 25 N.C.App. 14, 212 S.E.2d 205, cert. denied, 287 N.C. 261, 214 S.E.2d 433 (1975). "A continuance ought to be granted if there is an apparent probability that it will further the ends of justice." State v. Gibson, 229 N.C. 497, 502, 50 S.E.2d 520, 524 (1948). Such probability arises upon the voir dire hearing in this motion. The denial of the motion to continue was prejudicial error. We cannot find beyond a reasonable doubt that it was harmless error. Chapman v. California, 386 U.S. 18, 87 S.Ct. 824, 17 L.Ed.2d 705 (1967).
The trial court did not make any findings upon constitutional grounds but based its order solely upon the discretion of the court. We hold defendant's counsel, Triggs & Hodges, did not have a reasonable opportunity to investigate, prepare and present their defense, which is a violation of the constitutional guarantees of right to assistance of counsel. Under the circumstances of this case, seventeen days was not a reasonable time for defendant's counsel to comply with defendant's constitutional right to assistance of counsel in his defense. While the prompt trial of criminal cases is to be encouraged, we must not allow justice to fall into Charybdis in seeking to avoid Scylla. In preventing delays, "courts should not try cases with such speed as to raise a suspicion that `wretches hang that jurymen may dine.'" State v. Gibson, supra at 502, 50 S.E.2d at 525.
With this holding we do not discuss the other assignments of error, which may not occur upon retrial.
The conviction and sentences are vacated and the actions remanded for
New trial.
MORRIS, C. J., and CARLTON, J., concur.
