In Sirois v. Weston, the Court of Appeal cites its decision in Hamilton for the principle that damage occurs when the plaintiff suffers a change in a position, not when the change of position monetises into a specific amount:
[11] … the plaintiff suffers damage sufficient to complete the cause of action when he enters into the transaction, not when the loss is monetized into a specific amount.
This is an essential principle in any limitations analyses. The Limitations Act applies to “claims” (as defined by s. 1) pursued in court proceedings, and damage is an element of a “claim”.
What is not an essential principle in any Limitations Act analysis is the accrual of the cause of action. Cause of action accrual determined the commencement of time under the former act. If you look it up, you’ll see that limitation periods commenced when the cause of action arose. Now look at the Limitations Act, and you’ll see that the words “cause of action” do not appear at all. This is because MAG recommended removing the cause of action as determinative of the commencement of time in 1991 because three centuries or so of cause of action accrual had demonstrated that it was a pretty lousy animating principle of a limitations scheme.