Unit of account L.S.D units in ratio 240:12:1. The Florentine gold florin, the French franc and the electoral rheingulden all became pounds (240 denari) of account. Units of account would often survive over 100 years despite the original coins changing composition and availability (e.g. the Castilian maravedi). A modern unit of account is the European Currency Unit, used in the European Union from 1979 to 1998; its replacement in 1999, the Euro, was also just a unit of account until the introduction of notes and coins in 2002. Unit of account is the main way of calculating a carrier or ship owner's liability
Poland and the euro Poland and the euro Poland does not use the euro as its currency. However, under the terms of their Treaty of Accession with the European Union, all new Member States "shall participate in the Economic and Monetary Union from the date of accession as a Member State with a derogation", which means that Poland is obliged to eventually replace its currency, the złoty, with the euro. There is no target date for Polish euro adoption, and no fixed date for when the country will join ERM-II (the fifth euro convergence criterion). The country's former Deputy Prime Minister Janusz Piechociński has