In Batchelder v. Tweedie, 294 A.2d 443 (Me. 1972), the Court considered the question of whether a statute governing pre-judgment interest was procedural or substantive.
The Court observed that statutes establishing the "measure of damages" are a "matter of substance." Id. at 444. Procedural statutes, on the other hand, are those that "control the parties' conduct of the trial." Id.
The Court concluded that pre-judgment interest is a procedural issue because the statute increases the defendant's liability for pre-judgment interest is increased if the defendant is responsible for delays during litigation, and because the statute tolls the accrual of interest when the plaintiff is responsible for delays. Id. at 444-45.
In other words, the statute governing pre-judgment interest "exhibits a legislative intention to advance a remedial purpose, not to introduce new policy." Id. at 445.