An Etymological Dictionary of the German Language/Annotated/Woche
Woche, feminine, ‘week,’ from the equivalent Middle High German woche, Old High German wohha, usually with an earlier vowel wëhha, feminine, a common Teutonic term based on a primary form, wikôn-. Compare Gothic wikô, Old Saxon wika, Dutch week, Anglo-Saxon wucu, wicu, English week, and the equivalent Old Icelandic vika, feminine. The assumption that Latin vices, ‘change,’ was adopted by the Teutons in the sense of ‘week’ is untenable, for were the notion ‘week’ borrowed from the Romans, it would have assumed a form corresponding to Italian settimana, French semaine (Old Irish sechtman), ‘week.’ The Teutonic origin of the word is supported by the fact that it is borrowed by Finnish (as wiika), as well as by wîce, singular, ‘alternate service,’ the Anglo-Saxon variant of wĭcu, which makes it probable that Woche meant ‘change’ (compare Wechsel). The assumption of a loan-word is, however, most strongly opposed by the genuine Teutonic names of the days of the week, which prove the existence of a developed chronology in the pre-historic period.