Among these days "at some working day during the close to long run" is from late 15c. A kind of days "per day of misfortune, day when almost nothing goes ideal" is by 1924. Старый Новый Год (Old New 12 months) Though this holiday will not be officially daily off, https://spencerxacce.verybigblog.com/37613677/the-smart-trick-of-word-holiday-that-nobody-is-discussing