[¶ 1.] This is an appeal by the State of South Dakota (State) from a judgment of the First Judicial Circuit, Bon Homme County, dismissing the indictments of Dennis A. Hawk (Hawk) and Shay L. Sorensen (Sorensen) with prejudice for a violation of SDCL 23A-44-5.1 (the 180-day rule). We reverse and remand for trial.
*683FACTS AND PROCEDURE
[¶ 2.] Defendants Hawk and Sorensen were arrested without warrants on Saturday, September 27, 1997, after a routine traffic stop revealed they were in possession of a controlled substance - methamphetamine. They were immediately taken to Bon Homme County Jail. On the following Monday, September 29, 1997, the lay magistrate judge without the defendants’ personal presence, set bond and signed orders releasing both on. bond. Bond requirements included submission to random PBT and urinalysis tests, signing waiver of extradition rights and Sorensen was to remain at his residence when he was not at work. A criminal complaint was never filed against either defendant.
[¶ 3.] The State intended to take this matter before the grand jury. The grand jury met on November 4, 1997 and returned an indictment against both defendants. Both parties first appeared before a judicial officer on a charging document, in this case an indictment, on November 18, 1997. The trials for Sorensen and Hawk were set for April 22,1998.
[¶ 4.] Hawk and Sorensen filed a motion to dismiss for a violation of the 180-day rule. A hearing on the motion was held April 7, 1998 and a subsequent hearing followed on May 12, 1998. The trial court found the 180-day rule commenced on September 29, 1997, and expired on March 28, 1998. The trial court did not find the delay was attributed to either defendant and dismissed the charges against the parties with prejudice.
[¶ 5.] On appeal, the State raises the following issue:
Whether Sorensen’s and Hawk’s criminal trials were scheduled within 180 days as computed under SDCL 23A-44-5.1
STANDARD OF REVIEW
[¶ 6.] The trial court’s findings of fact are reviewed under the clearly erroneous standard. State v. Pellegrino, 1998 SD 39, ¶ 23, 577 N.W.2d 590, 599 (citing State v. Shilvock-Havird, 472 N.W.2d 773, 776 (S.D.1991)). “However, we review the determination of whether the period has expired, as well as what constitutes good cause for delay, under a de novo standard.” Pellegrino, 1998 SD 39, ¶23, 577 N.W.2d at 599 (citing State v. Fowler, 1996 SD 79, ¶ 10, 552 N.W.2d 391, 392 (citing State v. Cooper, 421 N.W.2d 67, 69 (S.D.1988))).
ANALYSIS AND DECISION
[¶ 7.] Whether Sorensen’s and Hawk’s criminal trials were scheduled within 180 days as computed under SDCL 23A-44-5.1.
[¶ 8.] The sole issue before us is whether the State violated SDCL 23A-44-5.1. The State argues the 180-day period began November 18, 1997. This was the date the defendants had their first appearance on a charging document before a judicial officer. However, the trial court found the 180-day period commenced on September 29, 1997, when Sorensen and Hawk “appeared” before the lay magistrate judge who set bond and signed orders releasing both on bond.
[¶ 9.] The trial court took issue with the State’s failure to file a complaint within what it determined to be a reasonable time. The court found the failure to file the charging document sooner, not to be filing within a reasonable time and to have potential for abuse. However, in this case the trial court did not identify any intentional abuse on the part of this particular prosecutor. In essence, finding this Court did not address this issue when it adopted the 180-rule, the trial court added another factor to be taken into account as to when the 180 days commences to run: when the prosecutor should have filed a complaint.
[¶ 10.] a. SDCL 23A-U-5.1
[¶ 11.] The 180-day rule provides:
(1) Every person indicted, informed or complained against for any offense shall be brought to trial within one hundred *684eighty days, and such time shall be computed as provided in this section.
(2) Such one hundred eighty day period shall commence to run from the date the defendant has first appeared before a judicial officer on an indictment, information ■ or complaint. As to indictments, informations, complaints or orders for a néw trial pending on July 1, 1991, such one hundred eighty day period shall commence to run from July 1, 1991.
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(Emphasis added).
[¶ 12.] The 180-day rule was adopted by this Court in January 1985 and took effect July 1,1985. State v. Hoffman, 409 N.W.2d 873, 374 (S.D.1987). The rule was initially intended to address ineffective scheduling practices. Id. at 375. We have stated that it creates a right to disposition of a criminal case within 180 days unless good cause may be shown for delay. Id. The 180-day rule is a procedural rule of court and not a constitutional requirement. Fowler, 1996 SD 79, ¶ 11, 552 N.W.2d at 393. “Violation of the 180-day rule is not synonymous with violation of a constitutional right to a speedy trial.” Id. (Citing State v. Erickson, 525 N.W.2d 703, 711 (S.D.1994); Hoffman, 409 N.W.2d at 375).
[¶ 13.] The language of this rule clearly provides the 180-day period begins to run when the defendant makes a first appearance on a charging document before a judicial officer. Based on the reasoning below, we find the trial court erred in its analysis and interpretation of the 180-day requirement.
[¶ 14.] The trial court found the 180-day period began to run on the date the prosecution should have filed the charging document under SDCL 23A-44-5.1 - that date being September 29, 1997, when the parties were granted bond by the magistrate although they did hot make a personal appearance as a part of that procedure. However, the rule does not read, the 180-day period will commence when the prosecution should have filed the charging document. The rule provides two requirements relevant to the issue now before us for the 180-day period to commence: 1) the defendant appears on a charging document; and 2) before a judicial officer. “This court assumes that [court rules] mean what they say.... ” Cf. In re Famous Brands, Inc., 347 N.W.2d 882, 885 (S.D.1984) (citation omitted). “When the language of the [rule] is clear, certain, and unambiguous, there is no occasion for construction, and the court’s only function is to declare the meaning of the [court rule] as clearly expressed in the [rule].” Cf. Mid-Century Ins. Co. v. Lyon, 1997 SD 50, ¶9, 562 N.W.2d 888, 891 (citation omitted).
[¶ 15.] The defendants had their first appearance before a judicial officer on a charging document, or the indictments on November 18, 1997, not September 29, 1997. Their trials were scheduled to begin within 180 days of that date. Because both cases were scheduled to go to trial within 180 days of the date they first appeared before a judicial officer on a charging document, there is no violation of SDCL 23A-44-5.1. We reverse and remand to the trial court for trial.
[¶ 16.] MILLER, Chief Justice and KONENKAMP, Justice, concur. [¶ 17.] SABERS and AMUNDSON, Justices, dissent.