The Slavic system of day names is a historical hybrid: an older numerical five-day week (Monday–Friday) was expanded by two days (Saturday and Sunday) into a seven-day week with the adoption of Christianity. The semantic bases of the day names are uniform across the Slavic languages with the sole exception of Ru voskresenʹe ‘Sunday’, lit. ‘resurrection (day)’.

Monday (PSl *ponedělьnikъ ‘after Sunday’; see below) is a compound, possibly modeled on Go afarsabbatē dags ‘Sunday’, lit. ‘after the Sabbath’ (or Gr προσάββατον prosábbaton ‘Friday’, lit. ‘before the Sabbath’; Buck 19…