(dissenting).
This court has the inherent and statutory authority to promulgate rules regulating pleadings and procedure in the courts of this state. See Minn.Stat. § 480.051 (1996); State v. Willis, 332 N.W.2d 180, 184 (Minn.1983). However, the majority’s strained application of a rule of civil procedure to an administrative proceeding raises, in my view, serious concerns about the separation of powers, while skirting the important constitutional issue before us. I respectfully dissent.
Long ago, this court acknowledged that the legislature could delegate quasi-judicial power over workers’ compensation matters *570to an administrative body. See Breimhorst v. Beckman, 227 Minn. 409, 431-433, 35 N.W.2d 719, 732-34 (1949). Along with the power to enact such enabling legislation, the legislature possesses- the power to determine when it becomes effective. See 2 Norman J. Singer, Sutherland on Statutes and Statutory Construction § 33.07 (5th ed. 1993) (“The power to enact laws includes the power to fix a future effective date.”). Our job, as we recently stated, “is to ascertain and effectuate legislative intent. We presume that plain and unambiguous statutory, language manifests legislative intent. If statutory language is plain and unambiguous, the court must give it its plain meaning.” In re Welfare of J.M., 574 N.W.2d 717, 721 (Minn.998) (citations omitted). “[T]he letter of the law shall not be disregarded under the pretext of pursuing the spirit.” Minn.Stat. § 645.16 (1996).
I am unpersuaded by the majority’s reliance upon Minn: R. Civ. P. 6.01. Minnesota courts have applied Rule 6.01 only when it is necessary to compute the passage of time. See, e.g., Wertish v. Salvhus, 558 N.W.2d 258, 258 (Minn.1997) (applying Minn. R. Civ. P. 6.01 to statute that required motion to be filed within ten days of the verdict’s entry).1 If the Workers’ Compensation Act, Minn. Stat. eh. 176 (1996), were silent as to when an apportionment proceeding is instituted, it might be permissible for this court to borrow from its rules of civil procedure in an effort to effectuate the legislature’s intent. However, in this case, the legislature plainly and unambiguously provided that the 1995 amendment to Minn.Stat. § 176.191 became “effective for apportionment proceedings instituted after July 1, 1995.” Act of May 25, 1995, eh. 231, art. 2, § 112, 1995 Minn. Laws 1977, 2072.2 The Act also plainly and unambiguously states that “all proceedings under this chapter are initiated by the filing of a written petition * * * with the commissioner,”' Minn.Stat. § 176.271, subd. 1 (Í996), and that “filing” is “completed by the receipt of the document at the * * * department,” id. § 176.275, subd. 1 (1996). The legislature established a date certain, one which does not require us to “compute a period of time” using Minn. R. Civ. P. 6.01 or any other rule promulgated by this court.3
Maplewood’s claim for contribution and/or reimbursement was not received until Monday, July 3, 1995; thus, under the Workers’ Compensation Act, its equitable contribution proceeding was not initiated until that date. The majority fails to explain why a proceeding that was “initiated” on July 3, within the meaning of section 176.271, was not “instituted after July 1,” within the meaning of the 1995 amendment. Surely the word “after” is not ambiguous. Cf. Parkinson v. Branden-burgh, 35 Minn. 294, 296, 28 N.W. 919, 920 (1886) (interpreting an act which provided that it took effect “from and after” the date of passage; holding that the phrase excluded the day the act was passed). I would hold that Maplewood’s petition is subject to the 1995 amendment.
*571In its haste to dispose of this appeal, the majority has failed to address the more significant issues presented: whether the arbitration provisions of the 1995 amendment permit an arbitrator to make the legal determination of whether an earlier injury substantially contributed to the later injury, and whether the arbitrator’s decision is “conclusive on the issue of apportionment” to the extent that there is no right of appeal. I would hold that arbitrators may decide the contribution issue, and I would interpret the arbitration provision so as to preserve judicial review of arbitrators’ decisions.
The 1995 amendment to section 176.191 in no way limits an arbitrator’s power to determine whether the earlier injury substantially contributed to the later injury. “Generally, * * * arbitrators are the final judges of both law and fact.” Johnson v. American Family Mut. Ins. Co., 426 N.W.2d 419, 421 (Minn.1988). In only one circumstance — automobile reparation — have we held that an arbitrator is limited to deciding fact issues, and even in that case we stated that it was within the power of the arbitrator, as factfinder, to find a party negligent. See id. at 421-22. In contrast to automobile reparation, an arbitrator making a substantial contribution determination needs only to apply the statute, not interpret it. I see no reason why this determination, like a finding of negligence, cannot be made by an experienced arbitrator.
Whether the 1995 amendment violates due process presents a closer question. • The amendment’s reference to the “conclusive” • effect of an arbitrator’s equitable apportionment determination is difficult to square with past statements of this court. We have stated before that “[d]ue process requires notice before judgment and an opportunity to be heard in an orderly proceeding adapted to the nature of the case, and the right of appeal from or review of a decision regarded by a litigant as unjust.” Hunter v. Zenith Dredge Co., 220 Minn. 318, 326, 19 N.W.2d 795, 799 (1945) (emphasis added); cf. Breimhorst, 227 Minn, at 433, 35 N.W.2d at 734 (holding that the separation of powers was not violated by the legislature’s delegation of quasi-judicial powers to the predecessor of DLI “as long as the commission’s awards and determinations [were] not only subject to review by certiorari, but lack[ed] judicial finality” absent the entry of judgment by a court). Consistent with our earlier decisions, I would hold that the 1995 amendment preserves the right of judicial review and merely codifies, by use of the word “conclusive,” the deferential standard we ordinarily have employed in reviewing arbitrators’ decisions. See, e.g., State v. Minnesota Ass’n of Prof'l Employees, 504 N.W.2d 751, 754-55 (Minn.1993) (“Every reasonable presumption must be exercised in favor of the finality and-validity of [an] arbitration award:”).
STRINGER, Justice(dissenting).
I join in the dissent of Justice Tomljano-vich.
. Likewise, computation of a time period was necessary in the workers’ compensation case cited by the majority. In Stordahl v. Northern Hydraulics, the Workers' Compensation Court of Appeals’ rules specified that appellants’ briefs must be filed 30 days after the court received transcripts. See No. 476-82-1959, 1993 WL 491338, at *3 (Minn. Workers’ Comp. Ct.App. Oct. 27, 1993). However, in the employee-appellant’s case, the thirtieth day fell upon a Sunday, and the employee-appellant filed his brief the following day, Monday. See id. Because its rules were silent on the issue, the Workers’ Compensation Court of Appeals applied Minn. R. Civ. P. 6.01 and held that the brief was filed timely. See id.
. Contrary to the majority’s assertion, application of the 1995 amendment would not ”den[y] [Greeley] the ability to proceed with its petition.” It would merely change the manner in which Greeley proceeds.
.In applying Minn. R. Civ. P. 6.01 to this matter, the majority has overlooked a rule that is far more analogous to the case before us: Under our rules of civil procedure, a civil action is "commenced” by service of a summons, but when the summons is served by mail, the action does not "commence” until service is acknowledged. Minn. R. Civ. P. 3.01(b). Surely the institution of an equitable apportionment proceeding is more akin to the commencement of a civil action than the filing of a responsive pleading. Under rule 3.01(b) and Minn.Stat. §§ 176.271 and 176.275, the proceeding could not have been commenced or instituted any sooner than July 3, the earliest opportunity the department had to acknowledge its receipt of Maplewood’s petition.