Conn. Gen. Stat. § 50a-55: Determination of amount of payment of certain contract claims.

(a) If an amount contracted to be paid in a foreign money is measured by a specified amount of a different money, unless otherwise agreed, the amount to be paid shall be determined on the appropriate conversion date.

(b) If an amount contracted to be paid in a foreign money is to be measured by conversion from a different money at the exchange rate prevailing on a date prior to default, unless a longer time is agreed, that exchange rate applies only for payments made in a reasonable time after default, not to exceed thirty days. Conversion thereafter will be made at the bank-offered spot rate on the conversion date.