Slovakia is also the first country that used to be in the Soviet orbit to join the eurozone - while Slovenia also was communist ruled, it was part of Yugoslavia, which kept its distance from Moscow.
The euro was introduced on financial markets on Jan. 1, 1999, and notes and coins first came into circulation in 2002. The zone widened to 15 countries in January 2008 when Cyprus and Malta joined; the other members are: Belgium, Germany, Ireland, Greece, Spain, France, Italy, Luxembourg, the Netherlands, Austria, Portugal, Slovenia and Finland.
Slovakia's old currency will be in circulation alongside the euro until Jan. 16. Banks also planned to open over the weekend to aid the transition.
The eurozone has a new member. Slovakia has just become the sixteenth state in the European Union to adopt the single currency. This is a remarkable turnaround.
The eurozone gets a new member on the 1st of January 2009. From midnight Slovakia swaps the koruna for the Euro.