Christian feast day: Cyril and Methodius (a public holiday in Czech Republic and Slovakia)

Cyril and Methodius were brothers, Byzantine Christian theologians and missionaries. For their work evangelizing the Slavs, they are known as the "Apostles to the Slavs".

The Czech Republic, also known as Czechia and historically known as Bohemia, is a landlocked country in Central Europe. The country is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the southeast. The Czech Republic has a hilly landscape that covers an area of 78,871 square kilometers (30,452 sq mi) with a mostly temperate continental and oceanic climate. The capital and largest city is Prague; other major cities and urban areas include Brno, Ostrava, Plzeň and Liberec.

Slovakia, officially the Slovak Republic, is a landlocked country in Central Europe. It is bordered by Poland to the north, Ukraine to the east, Hungary to the south, Austria to the west, and the Czech Republic to the northwest. Slovakia's mostly mountainous territory spans about 49,000 km² (19,000 sq mi), hosting a population exceeding 5.4 million. The capital and largest city is Bratislava, while the second largest city is Košice.