Appellant contends, inter alia,1 that the lower court erred in granting the Commonwealth’s two petitions for extension of time pursuant to Pa.R.Crim.P. 1100(c). We agree and, accordingly, vacate the judgment of sentence and discharge appellant.

The complaint in this case was filed on April 19, 1977. The trial did not begin until December 9, 1977, 233 days after the complaint was filed. Trial should have begun by October 17,1977, unless the period of delay beyond 180 days was either excluded under Rule 1100(d) or properly extended by court order under Rule 1100(c). The record indicates that this case was listed for trial on June 13, 1977. On that date, the lower court granted a continuance until July 5, 1977, because the defense was not ready. On July 5, 1977, the court granted a continuance until August 9, 1977, because a Commonwealth witness was on vacation. On August 9, 1977, the Commonwealth and the defense jointly requested a continuance because witnesses were not present. The case was continued until September 26, 1977. There is no indication in the record why trial did not begin on September 26. On October 11, 1977, the Commonwealth was granted a continuance until October 26, 1977, because the arresting officer was out of the country. On October 17, 1977, the Commonwealth filed a timely petition for an extension of time under Rule 1100(c). This petition was a form petition, which merely contained the unsupported assertion that the Commonwealth was unable to try this case within the 180 day period “[djespite due diligence.” On November 3, 1977, appellant filed an answer to the Commonwealth’s petition and a motion to dismiss. On November 4, 1977, the lower court held a “hearing.” The full discussion at that proceeding concerning the petitions was as follows:

THE COURT: 4-19-77, initiation date; 10-17-77, normal run date. Commonwealth filed their petition on 10-17, therefore timely filed.

*1396-13 to 7-5, defense request, not ready, twenty-two days.

8-9 to 9-26, a period of forty-eight days, joint application, a period of twenty-four days.

Twenty-two and twenty-four are forty-six; thirty day credit brings you down to sixteen.

The petition is timely filed, therefore, I’ll make a finding of due diligence.

The lower court granted the Commonwealth’s petition and extended the time for trial until November 15, 1977. On November 15, 1977, the Commonwealth filed a second petition for extension of time. On November 16,1977, appellant filed an answer. See note 2 infra. Following a jury trial, appellant was convictéd of criminal trespass and possession of instruments of crime. The lower court denied appellant’s post-trial motions and imposed sentence. This appeal followed.

Rule 1100(d)(2) provides:

In determining the period for commencement of trial, there shall be excluded therefrom such period of delay at any stage of the proceedings as results from:

(2) any continuance in excess of thirty (30) days granted at the request of the defendant or his attorney, provided that only the period beyond the thirtieth (30th) day shall be so excluded.

Where more than one continuance is granted to the defense, 30 days must be subtracted from the length of each continuance in determining whether any period of time is excludable under Rule 1100(d)(2). Commonwealth v. Shields, 247 Pa.Super. 74, 371 A.2d 1333 (1977). See also Commonwealth v. Thomas, 251 Pa.Super. 386, 380 A.2d 833 (1977).

Because the continuance obtained by the defense on June 13, 1977, was for less than 30 days, no portion of the continuance can be excluded. The continuance obtained on August 9,1977, exceeded 30 days, and the period in excess of 30 days clearly could be excluded if the continuance were *140granted to appellant alone. However, Rule 1100(d)(2) excludes “such period of delay ... as results from . any continuance in excess of thirty (30) days granted at the request of the defendant or his attorney . . . .” (emphasis added). The August 9, 1977, continuance apparently was granted because witnesses for appellant and the Commonwealth did not appear for trial. Because the Commonwealth was not prepared to try the case on August 9, 1977, the delay in the proceedings caused by this continuance was not attributable to appellant. See Commonwealth v. Morgan, 484 Pa. 117, 123, 398 A.2d 972, 974-75 (1979) (“the concern of the Rule is the delay in the commencement of trial and section (d) seeks to prevent the Commonwealth from being accountable for those delays in the commencement of trial where they result from actions properly attributable to the defense”). Therefore, no part of the delay caused by this continuance is excludable under Rule 1100(d)(2).

“Under Rule 1100(c), the Commonwealth should be granted an extension of time for commencement of trial if it can demonstrate on the record that trial [can]not be commenced within the prescribed period despite its due diligence.” Commonwealth v. Brown, 252 Pa.Super. 365, 368, 381 A.2d 961, 963 (1977). In Commonwealth v. Ehredt, 485 Pa. 191, 401 A.2d 358 (1979), our Supreme Court stated:

The Commonwealth has the burden, by a preponderance of the evidence, of showing it has met the requirements of Rule 1100(c). . . . Furthermore, in reviewing a hearing court’s ruling that the Commonwealth has met its burden, we consider only the evidence presented by the Commonwealth and so much evidence, as fairly read in the context of the record as a whole, remains uncontradicted.

Id., 485 Pa. at 194, 401 A.2d at 360. Although a continuance for less than 30 days is not excludable under Rule 1100(d)(2), “defense-requested continuances may realistically obstruct diligent efforts by the Commonwealth to try an accused and *141may, therefore, justify an extension under Rule 1100(c).” Commonwealth v. Mancuso, 247 Pa.Super. 245, 253-54, 372 A.2d 444, 448 (1977). See also Commonwealth v. Garnett, 258 Pa.Super. 115, 120, 392 A.2d 711, 713 (1978) (“the entire period of delay resulting from a continuance requested by the defense is a factor to be considered in determining whether the Commonwealth has exercised due diligence and is, as a result, entitled to an extension”).

“While the unavailability of a witness may be a relevant factor in determining whether an extension should be granted, . . . ‘[m]ere assertions of due diligence and unproved facts, do not establish cause for an extension under Rule 1100(c).’ ” Commonwealth v. Ehredt, supra, 485 Pa. at 195, 401 A.2d at 361 (quoting Commonwealth v. Antonuccio, 257 Pa.Super. 535, 537, 390 A.2d 1366, 1367 (1978)). Thus, “a bare statement by the Commonwealth’s attorney that several witnesses are ‘unavailable,’ without more, does not establish ‘due diligence’ . .” Id., 485 Pa. at 195, 401 A.2d at 360-61.

In the instant case, at the November 4, 1977, hearing, the Commonwealth produced no evidence in support of its form petition to extend. The only possible grounds for an extension appearing on the record are the four continuances. We conclude that the Commonwealth has not met its burden of showing due diligence to justify an extension on the basis of any of the continuances. There is no evidence that either the June 13 continuance obtained by appellant or the August 9 joint continuance “obstructed] diligent efforts by the Commonwealth to try [appellant],” Commonwealth v. Mancuso, supra. Moreover, although the absence of a Commonwealth witness may justify an extension under Rule 1100(c), the failure of the Commonwealth in the instant case to demonstrate its due diligence precludes the granting of an extension based on either of the continuances obtained by the Commonwealth. See Commonwealth v. Ehredt, supra. *142Therefore, the lower court erred in granting the Commonwealth’s first extension petition under Rule 1100(c).2

Judgment of sentence vacated and appellant discharged.

dissenting:

I dissent. Here, appellant does not allege any time is properly excludable under Rule 1100(d), but rather attacks the validity of two orders of the court granting the Commonwealth’s applications for extensions of time to commence trial, Rule 1100(c).1 The first such application was *143timely filed2 on the 180th day and appellant’s answer opposing such motion followed shortly thereafter. At a hearing on the application held November 4, 1977, it was established the defense had requested two continuances, while the Commonwealth had requested one continuance due to the unavailability of witnesses. The court thus found the Commonwealth could not proceed to trial within the time required, despite due diligence, and granted an extension of time to November 15, 1977. Appellant argues and the majority agrees that the Commonwealth did not sustain its burden of proving due diligence, which it must do by a preponderance of the evidence, Commonwealth v. Mitchell, 472 Pa. 553, 372 A.2d 826 (1977), and that the court should not have extended the time. I disagree. It is well-settled that defense requests for continuances may obstruct efforts by the Commonwealth to try an accused and may, therefore, justify an extension under Rule 1100(c),3 Commonwealth v. Garnett, 258 Pa.Super. 115, 392 A.2d 711 (1978); Commonwealth v. Brown, 252 Pa.Super. 365, 381 A.2d 961 (1977); Commonwealth v. Mancuso, 247 Pa.Super. 245, 372 A.2d 444 (1977).

In Commonwealth v. Brightwell, 486 Pa. 401, 406 A.2d 503 (1979), Justice Nix, writing in support of affirmance by an equally divided court, articulated the common sense rule which ought to be applied in this and in similar cases. “We know of no case,” he wrote, “wherein the right to a speedy trial has been violated when the cause for the delay has been properly attributable to the defendant. To the contrary, where the defendant has deliberately caused the delay, he *144has been prevented from taking advantage of his own wrong.” 406 A.2d at page 505.

Similarly, the absence of a Commonwealth witness may provide the basis for an extension order. Commonwealth v. Jenkins, 248 Pa.Super. 300, 375 A.2d 107 (1977); Commonwealth v. Lane, 245 Pa.Super. 146, 369 A.2d 335 (1976). Under these facts, we find no abuse of discretion in the 29 day extension granted to the Commonwealth.

The prosecution’s second request for an extension was filed November 15,1977 and appellant’s answer followed the next day. At the hearing on November 28, 1977,4 it was established that on the day appellant’s trial was listed, November 14, 1977, appellant was in custody on another charge and was “not brought down” by the sheriffs. The court found the Commonwealth had been duly diligent, but through sheriff delay, trial could not commence within the time allotted. I agree. Here the Commonwealth had done all it was required to do in order to bring appellant to trial, yet, through administrative delay it could not have foreseen, the Commonwealth’s attempt to commence trial was frustrated. It is well-settled that the Commonwealth may seek an extension if pretrial delay is caused by actions beyond the control of the court system, the defendant, and the prosecution. Commonwealth v. Metzger, 249 Pa.Super. 107, fn. 4, 375 A.2d 781, fn. 4 (1977). This case is thus akin to those where we found a valid Rule 1100(c) extension order due to judicial or other administrative delay in bringing an accused to trial. Commonwealth v. Cimaszewski, 261 Pa.Super. 39, 395 A.2d 931 (1978); Commonwealth v. Vickers, 260 Pa.Super. 479, 394 A.2d 1027 (1978); Commonwealth v. Alvin, 257 Pa.Super. 290, 390 A.2d 827 (1978); Commonwealth v. Brown, 251 Pa.Super. 179, 380 A.2d 436 (1977); Commonwealth v. Rambo, 250 Pa.Super. 314, 378 A.2d 953 (1977). I *145would rule that the prompt trial mandate of Rule 1100 was satisfied,5 and affirm the judgment of the court below.