Where does “četrtek” come from?
četrtek (Slovene) comes from Proto-Slavic četvьrtъkъ, from Proto-Slavic četvьrtъ, from Proto-Balto-Slavic ketwirtas, from Proto-Indo-European *kʷetwr̥tós.
četrtek (Slovene): Thursday
Ancestry of “četrtek”, step by step