Czech no relation 4
Fourth day
In Slavic languages and in Chinese, this day's name is "fourth" (Slovak štvrtok, Czech čtvrtek, Slovene četrtek, Polish czwartek, Russian четверг chetverg, Bulgarian четвъртък, Serbo-Croatian четвртак / četvrtak, Macedonian четврток, Ukrainian четвер chetver). Hungarian uses a Slavic loanword "csütörtök". In Chinese, it is 星期四 xīngqīsì ("fourth solar day"). In Estonian it's neljapäev, meaning "fourth day" or "fourth day in a week". The Baltic languages also use the term "fourth day" (Latvian ceturtdiena, Lithuanian ketvirtadienis).
no relation