The sole issue raised in the instant appeal is whether the Appellant was tried in the Philadelphia Municipal Court within the time constraints imposed under Rule 6013 of the Pennsylvania Rules of Criminal Procedure, Pa.R.Cr.P. 6013. Since we find that Appellant was not tried within the time period set forth by Rule 6013, the judgment of sentence is reversed and Appellant is discharged.
The Appellant, Tyrone Haynes, was arrested on July 18, 1981, and charged with aggravated assault, simple assault and reckless endangerment of a person arising out of an altercation in a laundromat in Philadelphia. The preliminary arraignment was held on July 19, 1981, at which time a trial date was set for August 12, 1981 in Philadelphia Municipal Court. On August 12, 1981, Appellant, through counsel, requested and was granted a continuance until September 29, 1981. On September 29, 1981 the Appellant did not appear, a bench warrant was issued and the Commonwealth orally requested an extension of time for trial under Rule 6013. The record establishes the Commonwealth knew that as of October 16, 1981, Appellant was in the custody of the United States Army in the stockade at Fort Dix, New Jersey on the charge of being away without leave (AWOL).
On or about March 24, 1982, the Appellant was arrested in Philadelphia and accorded a bench warrant hearing on March 26, 1982. The record is silent as to the whereabouts or actions of Appellant between October 16, 1981 and March 24, 1982, nor does it state the date Appellant was released from Army custody. When asked by the trial court the Commonwealth was unable and the Appellant unwilling to *168give such information. In any case, Appellant was given a trial date of May 17, 1982, at the bench warrant hearing. For some reason, Appellant was not brought to court on the new date for trial and the case was continued until June 18, 1982. On June 18, 1982, Appellant’s counsel withdrew and the Defender Association of Philadelphia was appointed. A defense continuance was granted until August 3, 1982. On that date, the trial court granted the Commonwealth’s oral motion to extend under Rule 6013 and denied Appellant’s motion to dismiss for failure to comply with Rule 6013. Immediately after, the Appellant was tried and convicted and then sentenced to two years probation.
On August 17, 1982, Appellant filed a petition for a writ of certiorari to the Philadelphia County Court of Common Pleas requesting that said court order the Philadelphia Municipal Court to certify and send a complete transcript to the Common Pleas Court and that his conviction be reversed and he be discharged based on an alleged violation of Rule 6013. On July 6, 1983, the petition for a writ of certiorari was denied after which Appellant filed this timely appeal.1
On June 28, 1974, the Supreme Court of Pennsylvania adopted Rules of Criminal Procedure for the Philadelphia Municipal Court effective July 1, 1974. Pa.R.Cr.P. 6000-6013. In doing so the Court prescribed certain rules of criminal procedure applicable only to cases instituted or transferred to the Philadelphia Municipal Court. Rule *1696013(a)(2) provides that trial in a Municipal Court case in which preliminary arraignment is held after June 30, 1975, shall commence no later than 120 days from the date on which the preliminary hearing is held. Subsection (c)(1) allows the Commonwealth to file a petition to extend the time for commencement of trial and subsection (d) prescribes that in determining the period for commencement of trial the following time is excluded: any period of time for which the defendant is unavailable or any time period covered by a defense continuance. Thus, Rule 6013 is remarkably similar to Rule 1100 of the Pennsylvania Rules of Criminal Procedure. Pa.R.Cr.P. 1100. We will accordingly review the instant case in a manner similar to Rule 1100 cases.
Appellant concedes that certain time must be excluded from the calculation of the period for commencement of trial under Rule 6013. Since Appellant was arrested on July 19, 1981, the mechanical run date for Rule 6013 was November 16, 1981. Appellant agrees that the period from August 12, 1981 until September 29, 1981, must be excluded because of the defense continuance and that the period of September 29, 1981 until October 16, 1981, should be excluded because of the Appellant’s unavailability, for a total of 66 excluded days. However, Appellant contends that the time period between the date the Commonwealth knew Appellant was in Army custody, October 16, 1981, and the date of Appellant’s later arrest, March 24, 1982, cannot be excluded because the Commonwealth failed to exercise due diligence in obtaining the custody of Appellant from the Army. In fact, Appellant argues that the Commonwealth did absolutely nothing to secure his custody from the Army and did not know his exact whereabouts during the period of October 16, 1981, until March 24, 1981. This, the Appellant contends, violates the Commonwealth’s duty to use due diligence under Rule 6013 to obtain custody of an accused who is in custody in another jurisdiction. The Commonwealth’s position is that the Appellant voluntarily absented himself from the jurisdiction of the Philadelphia Municipal *170Court and failed to inform the court as to his whereabouts violating a provision of his bail agreement. On this basis, the Commonwealth contends we should find that the Appellant was unavailable within the meaning of Rule 6013 and thus exclude the period of September 29, 1981 until March 24, 1981, from the determination of the period for commencement of trial under Rule 6013.
It is well settled in this Commonwealth that mere incarceration in another jurisdiction does not make a defendant “unavailable” within the meaning of Rule 1100(d) in the determination of whether to exclude a period of time in the computation of the 180 day period for the commencement of trial. Commonwealth v. Stange, 286 Pa.Super. 38, 428 A.2d 226 (1981); Commonwealth v. Emmett, 274 Pa. Super. 23, 417 A.2d 1232 (1979). The defendant will only be “unavailable” under Rule 1100(d) for the period of time during which his presence cannot be secured despite the due diligence of the Commonwealth. Commonwealth v. Stange, supra. Further, the Commonwealth has the burden of proving the defendant’s unavailability by a preponderance of the evidence. Commonwealth v. Wroten, 305 Pa.Super. 340, 451 A.2d 678 (1982). However, due diligence does not require perfect vigilance and care, but rather a reasonable effort. Commonwealth v. Polsky, 493 Pa. 402, 426 A.2d 610 (1981). Since Rule 6013 is similar to Rule 1100 we find the case law to be equally applicable to both rules.
The record reveals that the Commonwealth “knew” on October 16, 1981, that Appellant was incarcerated in Fort Dix, New Jersey in the custody of the United States Army. It was, thus, incumbent on the Commonwealth to make reasonable efforts to secure Appellant’s return to Pennsylvania. However, the record fails to show that the Commonwealth made any effort to secure Appellant’s custody and only arrested him through an apparent fortuitous consequence, although the record is not clear as to the circumstances surrounding the arrest. The only thing that is clear from the record is that custody of the Appellant was not secured directly from the Army.
*171At the pre-trial hearing on Appellant’s motion to dismiss under Rule 6013 the Commonwealth stated that it did not seek custody of Appellant because it believed that the Army would not return Appellant. However, there is no objective evidence in the record to support this belief. The subjective belief of the Commonwealth is not enough to sustain its burden of due diligence. On appeal, the Commonwealth has abandoned the above argument and instead argues that its duty of due diligence was vitiated by the Appellant’s violation of his bail agreement in leaving the jurisdiction and not reporting his whereabouts. The Commonwealth cites certain decisions of this Court in support of its position, specifically, Commonwealth v. Byrd, 325 Pa. Super. 325, 472 A.2d 1141 (1984); Commonwealth v. Colon, 317 Pa.Super. 412, 464 A.2d 388 (1983); and, Commonwealth v. Williams, 299 Pa.Super. 226, 445 A.2d 537 (1982). However, these cases are distinguishable from the case at bar. In the cases cited by the Commonwealth the accused was incarcerated in another jurisdiction, but the Commonwealth did not know the whereabouts of the accused. In such cases we have found the accused to be “unavailable” within the meaning of Rule 1100. However, in the instant case the Commonwealth knew where Appellant was incarcerated, and in such cases we have required a showing of due diligence in seeking the custody of the accused before we deem the accused “unavailable”. As we have already noted the Commonwealth has failed to meet its burden of proving due diligence.
Accordingly, we find that the days between October 16, 1981 and March 24, 1982, are not excludable from the calculation of the time for commencement of Appellant’s trial under Rule 6013. Since the number of days between the above two dates totals 160 it becomes obvious that Appellant was not tried within 120 days from his preliminary hearing. If the days Appellant concedes are excludable are added to the mechanical run date of November 16, 1981, the new run date was January 21, 1982. Appellant should have been tried on or before that date, and since he *172was not, the judgment must be vacated and Appellant discharged.
Judgment of Sentence vacated. Appellant discharged.
. While the procedural device of a writ of certiorari has been abolished by the Pennsylvania Supreme Court as a method of appealing a summary conviction before a district magistrate, Pa.R.Cr.P. 67(g), this Court had held that the writ of certiorari is alive and well in the Municipal Court of Philadelphia and that the Philadelphia County Court of Common Pleas may continue to issue writs of certiorari to the Philadelphia Municipal Court in non-summary criminal cases. Commonwealth v. Poindexter, 248 Pa.Super. 564, 567, n. 2, 375 A.2d 384, 386, n. 2 (1977). Since the instant case is a non-summary criminal case over which the Philadelphia Municipal Court has jurisdiction the petition for writ of certiorari by Appellant was procedurally proper. In addition, Appellant’s appeal of the denial of the writ within 30 days of the denial makes the appeal timely. Accordingly, the appeal of the denial of the petition for a writ of certiorari by the Philadelphia County Court of Common Pleas is properly before this Court.