The binding principle is that for purposes of applying currency conversion legislation (S.I. 33/2019), the relevant date is when the liability accrues and becomes payable, not when the underlying events or contributions occurred. In an insurance/pension context, the liability accrues when the insured event is established and payment is triggered (here, the date of termination), not the date of diagnosis or initial incapacity. Assets and liabilities denominated in US dollars immediately before the effective date of 22 February 2019 are converted to RTGS dollars at 1:1 when the liability is liquidated or discharged. Further, constitutional challenges must be properly pleaded as primary relief with full supporting arguments, and cannot be raised as alternative or by-the-way relief.